Devoted fans of any show are sure to catch little moments where things just don’t quite line up right. HIMYM fans are no different, and there are a fair amount of conflicting plot points throughout the past nine seasons. Here’s a complete list of everything I’ve observed, plus everything I’ve been able to find online. If you know of something that’s missing from the list, post it in the comments so I can update accordingly!

Be sure to read the comments to see all the catches that fans have found and noted. I don’t have this post fully updated and there is some quality stuff mentioned by readers.

The Big HIMYM Mistakes:

• Barney & Robin’s wedding date
• Penny’s age
• Proposal date
• St. Patrick’s Day 2008

The HIMYM Mistakes You Always Hear About:

• Marshall & fighting
• Lily & Marshall sharing a toothbrush
• Robin & team sports
• The Hot/Crazy scale
• The actor who plays Tom
• Robin & nicknames
• Barney’s ability to drive
• Barney & bad pictures

The Other HIMYM Mistakes:

• Ted & Natalie
• Marshall & painkillers
• Robin & strip clubs
• Barney & cooking naked
• Ted & Trudy
• Ted & vomiting
• Robin & guns
• Lily & Marshall’s song
• Lily’s dog allergy
• “Grinch”
• Barney’s first time
• Barney & funeral attire
• Robin’s aunt’s lover’s name
• Lily’s dad and the wedding
• Barney & the belt
• Marshall’s family at the wedding
• Canada’s tallest mountain
• Everyone’s spoiler alerts
• Simon’s band name
• Marshall & winking
• Robin & girl friends
• Barney & challenges
• The Mother & Louis

The Big HIMYM Mistakes

Barney & Robin’s Wedding Date:

In S8E13 “Band or DJ?”, Ted specifically says that the wedding date is May 25th, 2013. That puts the wedding on a Saturday. But the first episode of season nine (S9E1 “The Locket”) opens with a title of Friday, 11 am, 55 hours before the wedding. That means that the wedding must be on Sunday, May 26th. This Sunday date has held true thoughout the entire season, so it is clear that the season 8 date is a mistake.

Proposal Date:

At the end of S9E8 “The Lighthouse”, we see Ted at the Farhampton lighthouse with a girl named Cassie. This scene is in May 2013, as he meets her right before Barney and Robin’s wedding. Next comes a scene that is titled “Not 2 Years Later”, putting us at May 2015. Ted is at the lighthouse with The Mother, and he says “why couldn’t it have been you here with me two years ago?” This confirms that the proposal date is two years after Barney and Robin’s wedding, and therefore in May 2015.

A proposal date of May 2015, however, means that baby Penny was certainly conceived and almost certainly born before Ted proposed. This has been hard for some fans, because it seems like such a deviation from the traditional love story that Ted is seeking. But this isn’t a traditional love story, and the timeline has been confirmed as correct:

THE HIMYM MISTAKES YOU ALWAYS HEAR ABOUT

Marshall’s History With Fights:

In S1E3 “Sweet Taste of Liberty”, Marshall challenges a guy that he thinks is hitting on Lily. The guy is gay, and Marshall expresses his relief by saying “Oh thank God, I’ve never been in a fight before”. The gay guy’s boyfriend then punches Marshall out.

In S4E10 “The Fight”, however, Marshall repeatedly states that he has been in plenty of fights with his brothers. The gang laughs this off, because they image the Eriksen boys play fighting gently with multiple breaks for hot cocoa. At the end of the episode, Marshall punches the bartender that’s about to punch Ted. Doug the bartender goes down, because Marshall can actually hold his own. We see a flashback to the real fights between the Eriksen brothers, and they’re pretty brutal. How brutal? Well, the background music for these scenes is the infamous “Murder Train” by the Foreskins, and it’s totally appropriate for the WWE style, furniture breaking, balls to the wall, Fight Club worthy scene.

Marshall & Lily Sharing A Toothbrush:

In S5E14 “Perfect Week”, Lily and Marshall confess to both sharing a single toothbrush. Ted realizes that he has also been using this toothbrush, and thus Robin realizes that she used it as well when her and Ted were dating. Everyone is revolted. Lily and Marshall seem to have thought this was normal, but they realize it’s totally weird.

BUT in S1E14 “Zip Zip Zip”, we see Lily and Marshall brushing their teeth at the same time, using different toothbrushes.

Robin & Team Sports:

In S1E6 “Slutty Pumpkin”, Robin says she never played team sports.

BUT in S1E20 “Best Prom Ever”, Robin says she missed her high school prom because she had a field hockey game. Field hockey is a team sport. Also, in S4E6 “Happily Ever After”, we see a flashback to Robin kissing one of her male (ice?) hockey teammates. I believe Robin was the only girl on that team, but her father didn’t truly accept that he had a daughter until this moment. He had been treating her as a son ever since she was born and he named her Robin Charles Scherbatsky Senior.

The Hot/Crazy Scale:

In S3E5 “How I Met Everyone Else” Barney explains the Hot/Crazy scale, aka the Vickie Mendoza diagonal. “When Barney is explaining the Vicky Mendoza Diagonal, he gets his axes wrong. He implies that her stabbing him with a fork made her less hot, rather than more crazy, and that the boob job made her less crazy, rather than more hot. In fact, it would actually go right, up and then right again.” (It was too complicated for me to explain – thanks to the HIMYM wiki for this summary)

The Actor Who Plays Tom:

In S2E10 “Single Stamina”, Barney sees a picture on his brother James’ phone. The picture is of James and Tom, the man he is engaged to. Tom is a white guy.

BUT in S7E11 “The Rebound Girl”, we see Tom in person. In this episode he is played by a totally different guy that doesn’t look anything like original white guy Tom. Here, Tom is played by Jai Rodriguez. Now Tom is not a white guy.

Robin & Nicknames:

In S5E6 “Bagpipes”, Ted knows that something is amiss with Barney and Robin because they are using cutesy nicknames. Ted recalls that Robin hated such nicknames when they were dating, and she didn’t let him get away with calling her “Robsie Wobsie” and “Schebs”. She also does not let Ted call himself “T-Moz”.

BUT in S2E1 “Where Were We”, Robin calls Ted “Teddy Bear”. Further down the road, in S9E3 “Last Time in New York”, Robin and Barney refer to each other as “R-Train” and “B-Nasty”, respectively. I suspect this is just something about Ted that bugged Robin, but doesn’t necessarily bother her with her other people. Or, her and Barney just love one another so much that they have in some ways become that couple that uses cheesy nicknames.

Barney’s Ability To Drive:

In S2E17 “Arrivederci, Fiero”, Barney reveals that he hates Marshall’s Fiero. We see a flashback to Ted realizing that Barney doesn’t know how to drive, and attempting to teach him using Marshall’s car. The lesson does not go well, and at the end Barney still seems to lack the ability to drive more than 1 MPH.

BUT there are several earlier episodes that seem to indicate Barney’s ability to drive. In S1E22 “Come On”, Barney mentions having sex with Penelope two times in his car. This does not necessarily mean that he could drive then, though, and even owning the car may have been another Barney lie in an effort to get laid. In S4E11 “Little Minnesota”, we see a flashback to Barney driving Ted’s mom to the airport. This flashback is supposed to have occured right after S2E3 “Brunch”, which obviously aired before the Fiero episode. We also see him driving in S2E18 “Moving Day”, S4E23 “As Fast As She Can”, and S5E24 “Doppelgangers”.

Barney and Bad Pictures:

In S5E18 “Say Cheese”, we discover that Barney (supposedly) never takes a bad picture. Robin is repeatedly shown attempting to trick him into a bad pose or expression, but the picture always comes out flawless. Barney is also always in the same pose in every picture.

BUT starting in S1E2 “Purple Giraffe” we see the opening montage featuring photos of the gang. Barney is show in different positions and even looking really akward and unattractive in one. This is further disproved in S3E14 “The Bracket”, where Lily takes photos of Barney for her scrapbook of his misadventures. She is able to get pictures of him being beat up and of him running away; neither of those fit with his usual pose/expression.

THE OTHER HIMYM MISTAKES

Ted & Natalie’s Dating History:

In S1E4 “Return of the Shirt”, Ted talks about a girl from his past – Natalie. He explains that they dated three years ago and he broke up with her on her birthday. Ted and Natalie are both very clear in this episode that they haven’t seen eachother in three years. This episode shows us Ted dating her for three weeks and then breaking up with her on her birthday AGAIN. This episode aired in October of 2005, so he should have originally broken up with her in October of 2002, and not seen her since.

BUT in S5E18 “Say Cheese”, we see a flashback to Marshall comforting Natalie after Ted has broken up with her.  This memory is labeled February of 2005. This conflicts with Ted not seeing her for 3 years. Also, in S6E23 “Landmarks”, we see a series of undated flashbacks showing Ted getting back with his exes for stupid reasons. In one scene he runs out of whipped cream and then calls Natalie and asks if she wants to get back together. It is noted that they date for another three months. My best guess is that this moment is supposed to have occured in December of 2004, leading to the breakup in February of 2005. It could have happened after “Return of the Shirt” (10/2005) but they do mention in that episode that Natalie is married within a year. So it would have had to have happened between November of 2005 and November of 2006. The earlier time frame makes more sense given the dated flashback of them breaking up.

Marshall Taking Painkillers:

In S1E5 “Okay Awesome”, Marshall asks Barney for aspirin to ease his dental pain. Barney advises asking people in the bathroom, and Marshall emerges later under the influence of some unnamed drug. He then dances in a truly spectacular fashion:

BUT in S2E15 “Lucky Penny”, Marshall says he doesn’t believe in painkillers. This one isn’t as confusing as some others – it’s easy to imagine Marshall making an exception if he’s suffering from intense tooth pain.

Lily Peeing In Front Of Marshall:

In S1E14 “Zip Zip Zip”, Lily and Marshall talk about how they have never peed in front of one another.

BUT in S1E16 “Slutty Pumpkin”, Marshall has to take Lily to the bathroom because her costume is so complicated. Technically he could have helped her get out of it without seeing her pee, but it seemed to imply that he was there for the actual peeing. This is another one of those small technicalities that could be easily explained.

Robin & Strip Clubs:

In S1E9 “Belly Full of Turkey”, Robin ends up spending American Thanksgiving at the Lusty Leopard with Ted and Barney. At the time she seems fine with being in a strip club and appears to be enjoying herself.

BUT in S5E2 “Double Date”, Robin is angry at Barney for going to a strip club. This may be just because they are dating, and it’s entirely different to go to a strip club with your guy friends versus your boyfriend going to a strip club without you.

Barney & Cooking Naked:

Also in S1E9 “Belly Full of Turkey”, Marshall warns Ted that Barney cooks naked and is thus not a good prospect for a replacement roommate.

BUT in S2E5 “World’s Greatest Couple”, Barney shows Lily that he does not actually keep any food in his kitchen at all. Later, in S6E10 “Blitzgiving”, we see that Barney’s stove and oven are actually just cardboard displays. It is worth noting that Barney has clearly sustained himself in some manner throughout the years, so any/all of this could be more of Barney’s lies.

Ted & Trudy’s History:

We first meet Trudy in S1E10 “The Pineapple Incident”. Ted has a one night stand with her and she sneaks out via the fire escape the next morning. In this episode, Future Ted says the he left her a message, but she never called back.

BUT in S3E3 “Third Wheel”, Ted meets up with Trudy again. He says that he was going to call her, but he was too embarassed. So it is unclear whether Ted ever called her after the night of The Pineapple Incident.

Ted’s Vomiting History:

In S1E10 “The Pineapple Incident”, Ted proclaims that he is “vomit free since ’93!”

BUT in S1E10 “Game Night”, we discover that Ted “re-returned” and vomited on Robin’s doormat as of the pilot episode (set in September of 2005). This does not count as a continuity error since Ted is called on his lie and the group addresses the discrepancy.

Robin & Guns:

In S1E11 “The Limo”, Robin is visibly afraid of Not Moby’s gun.

BUT in S2E1 “Where Were We”, we discover that Robin is quite the gun enthusiast. She takes Marshall to the gun range to help him get over his depression from missing Lily. She also wears a necklace with a gun shaped pendant. In S2E4 “Ted Mosby: Architect” we learn that Robin usually carries a gun in her purse. In S2E18 “Moving Day” we learn that Robin has a subscription to Guns & Ammo magazine. There are many references throughout the series to Robin’s mastery of guns and her enthusiasm for them.

This isn’t really an error, but a possible character conflict. Season 2 and beyond Robin is the type of person that, when a person pulls a gun on her, would likely pull her own gun out in return. She would then proceed to either discuss how awesome guns are, or stand her ground against someone actually trying to hurt her.

With all that being said, Not Moby was a frightening character and you really can’t blame Robin for being taken aback.

Lily & Marshall’s Song:

In S1E17 “Life Among the Gorillas”, Lily and Marshall say that “their song” is “I Got You Babe” by Sonny and Cher.

BUT in S1E20 “Best Prom Ever”, Lily says that her and Marshall’s song is “Good Feeling” by the Violent Femmes. This is easily explained though – they have one song that they always do for karaoke, and one song that is their actual song from the day they met.

Lily’s Dog Allergy:

In S2E5 “World’s Greatest Couple”, Lily says can’t stay with Robin because she’s allergic to dogs, and Robin (at this point) has five dogs living with her.

BUT in S2E2 “The Scorpion and the Toad”, Lily spends time in Robin’s apartment, with the dogs present. She does not show any signs of having problems with allergies. Lily not having anywhere else to stay is the basis for the entire plot of “World’s Greatest Couple”, so the writers must have felt this was the easiest explanation. Lily is also shown petting Robin’s dogs in S2E6 “Aldrin Justice”.

In real life, actor Josh Radnor (who plays Ted) is actually allergic to dogs. Paramedics were called in during the filming of S2E16 “Stuff”, because Josh Radnor had a severe allergic reaction to the dogs in that episode.

“Grinch”:

In S2E11 “How Lily Stole Christmas”, we hear an old answering machine message where Ted refers to Lily as being a “grinch”. This was after she broke up with Marshall and went to San Francisco, so it makes sense that Ted would not be feeling positively towards her at all. Future Ted says that he didn’t actually say “grinch”, but instead said “a bad word. A very, very bad word”. Most people think that “grinch” is a substitute for the word “bitch”. The show creators, Craig Thomas and Carter Bays, have said that this was based on a real world incident and the word was actually “bitch”. The CBS website also used to have a glossary, which defined “grinch” as “bitch”.

BUT the word “bitch” is frequently used throughout the series, including many times by Lily herself. One of her catchphrases is even to say “youuuuu sonofabitch!” when she is angry at someone. This, combined with the random girl’s extreme reaction when she walked by and overheard the word, have led many to believe that “grinch” is actually a stand-in for the C-word. Lily also calls Ted’s mom to tell on him, and Ted’s mom then called him to lecture him about using “that word”. There is obviously a difference between calling someone a bitch jokingly and having one of your best friends specifically say that you are a bitch. But, when everything is considering, it really seems that “grinch” = C word in the world of HIMYM.

Barney’s First Time:

In S2E12 “First Time in New York”, Barney reveals that his first time was with his mom’s friend Rhonda. He was 23, she was 45, and she called him “Barry” the whole time. He says “for two weeks my comforter smelled like menthol cigarettes”.

BUT in S3E10 “The Yips” we see a flashback to Barney losing his virginity, and the big moment occured at Rhonda’s house. Barney’s sheets on his own bed should not have smelled like Rhonda, since they didn’t have sex on them. The only possible explanation is that Rhonda’s menthol cigarette scent was so pervasive that it got all over Barney and then rubbed off onto his sheets. That is gross.

Barney’s Funeral Attire:

In S2E14 “Monday Night Football”, Barney says that he does not wear suits to funerals. He feels that suits are for joyous occasions.

BUT in S6E14 “Last Words”, Barney wears a suit to Marshall’s dad’s funeral. Since this is the funeral for one of his best friend’s dad, though, he is probably just being respectful.

Robin’s Aunt’s Lover’s Name:

In S2E16 “Stuff”, Robin says that she has sent her dogs to live upstate with her aunt and her aunt’s live in “friend” named Betty. At this point Robin does not realize that her aunt and Betty are a lesbian couple.

BUT in S8E5 “The Autumn of Breakups”, Robin mentions her aunt again, but this time says her long term partner is named Maureen. This is the moment when Robin realizes that her aunt and Maureen (who may or may not be the same person as Betty) are lesbians. Both episodes seem to imply that this is a long term, commited relationship, but it is entirely possible that the aunt broke up with Betty and got together with Maureen at some point in between.

Lily’s Dad & The Wedding:

In S2E18 “Moving Day”, Lily responds to a joke and says that her dad isn’t going to pay for a second wedding.

BUT in S5E9 “Slapsgiving  2: Revenge of the Slap” we learn that Lily and her dad aren’t close at all. He wasn’t even invited to the wedding. Beyond that, he is constantly having financial problems due to his unsuccesful board game company, so it’s unlikely he could have paid for the wedding regardless.

Barney & The Belt:

In S2E19 “Bachelor Party”, Barney says he has been in a “ten-way”.

BUT in S3E3 “Third Wheel” Barney confesses to having panicked right before a potential three-way. He has not earned the belt yet (the established prize for whoever “rides the tricycle” first), which would imply that he lied about the ten-way. This is completely plausable, because Barney lies all the time. However, it is worth noting that a three-way is probably much more intimidating than a ten-way. In the former, Barney would have been solely responsible for pleasuring two women. In the latter, there are enough people involved that the pressure wouldn’t have all been on him.

Marshall’s Family Isn’t At The Wedding:

In S2E21 “Something Borrowed” and S2E22 “Something Blue” we see Marshall and Lily’s wedding day. We don’t actually see any of Marshall’s family, though, despite being introduced to his immediate family in S1E9 “Belly Full of Turkey”.

Canada’s Tallest Mountain:

In S3E7 “Dowisetrepla” Robin says that Lily has a pile of debt the size of Mount Waddington. She says this is the tallest mountain in Canada, but that honor actually goes to Mount Logan. Mount Waddington is the seond highest in British Columbia, and the 17th highest in the country.

Everyone’s Spoiler Alerts:

We learn about everyone’s particular “spoiler alert” habits that the other’s dislike in S3E8 “Spoiler Alert”. Some are well documented throughout the series – we have seen Ted correcting people, Marshall singing made up songs, Robin saying “literally” incorrectly, and Barney spacing out/using a weird high pitched voice/using corny catchphrases. Despite this, we have not heard Lily’s supposed loud chewing in any episode before or after. I personally don’t care because this is my favorite episode and I think it is possibly the funniest in the entire series.

Simon’s Band’s Name:

In S3E16 “Sandcastles in the Sand”, we learn that Robin’s ex-boyfriend had a band called The Foreskins. When she reunites with him, and the gang meets him, Ted jokingly asks why they named their band that. Simon seems to be serious when he replies that there were four of them, and they played without shirts. But, if that was the real reason, the band name would be The Four Skins.

We see band flyers in the flashbacks – and the Murder Train song credits when Robin is on air – that show the name is in fact The Foreskins. So basically this is just Simon being a dick to Ted.

Marshall & Winking:

In S6E13 “Legendaddy”, Marshall encourages the gang to tell him about his shortcomings. He feels that they have been holding back since the death of his father, and he wants things to get back to normal. Among others on the list is that Marshall cannot wink.

BUT in S2E8 “Atlantic City” we see Marshall winking at Ted and Barney.

Robin & Girl Friends:

In S9E4 “The Broken Code” Lily says that Robin doesn’t have any girlfriends.

BUT in S1E1 “Pilot”, S1E14 “Zip Zip Zip”, S4E8 “Woooo!”, S6E9 “Glitter”, and S6E16 “Desperation Day” we see Robin with various female friends.

Barney & Challenges:

In S9E9 “Platonish”, we see a flashback where Lily accuses Barney of only ever doing his own challenges. We have seen many instances, though, where Barney does in fact accept other’s challenges. The most notable one is in S4E19 “Murtaugh”. Ted has a list of things that they are all too old to do, and Barney takes that as a personal challenge.

We also see Barney as an old man picking up a woman in S4E4 “Intervention”.

It is true, though, that Barney’s challenges tend to be inspired by others, but not actually assigned by them. Barney often makes a challenge out of something that no one intended, expected, or even wants to see.

The Mother & Louis:

In S9E16 “How Your Mother Met Me”. we learn about The Mother’s relationship with Louis, her last boyfriend before Ted. We see them meet in a scene titled April of 2012, but then Narrator Ted says they dated and “for a couple years it was fine”. This doesn’t make sense, because The Mother meets Ted just one year later. I think that was just a small error but with these writers who knows. They could have more confusing tricks up their sleeve but I don’t think this is one of them.