Most beloved sitcoms are riddled with errors and gaffes.
Whether it’s due to a new team of writers retconning a main character’s backstory to explore new and funnier territory, or whether it’s the more run-of-the-mill oversights inherent in having to quickly produce 20+ episodes of television a year, there’s no denying that countless re-watches of our favourite sitcoms have yielded a sizeable list of mistakes.
King of the Hill, Seinfeld, M*A*S*H, Friends, The Simpsons, How I Met Your Mother, and It’s Always Sunny in Philadelphia, are just a few of the most iconic and acclaimed sitcoms ever produced.
However, they have let some errors slip by that only the eagle-eyed fans and devotees have noticed.
Sometimes these mistakes are not only forgiven but are actually welcome and vital – characters grow and evolve over time, and forgoing continuity in order to explore richer comedic, and sometimes dramatic, ground is certainly what’s called for in order to keep a series from stagnating or repeating itself.
At other times, though, these mistakes simply leaving most scratching their heads, wondering how or why the heck that happened.
Here are the 20 Mistakes In Iconic Sitcoms Only True Fans Noticed.
20 Charlie's Non-Existent Sister - It’s Always Sunny In Philadelphia
Charlie Kelly is considered to be both the wild card and the stupid one in the gang. Though he demonstrates a level of empathy and concern for social norms that the others are sorely incapable of, making him the most lovable member of the gang.
His characterization is well-drawn and consistent from season 1 onwards.
However, there are some minor flubs in his backstory.
In the episode “Charlie Got [Assaulted]”, Charlie mentions that he has a sister. Oddly enough, this sister is never seen, mentioned, or heard of again.
This little mistake is in keeping with a lot of sitcoms, where characters mention relatives who never show up or are mentioned later.
This could be because it was something possibly to be explored later or because there’s not much in the comedy tank for Charlie having a sister.
19 Sneaker mistake - How I Met Your Mother
How I Met Your Mother’s season 5 episode, “Girls Vs. Suits” is considered to be one of the best episodes the sitcom ever produced.
It’s got a lavish musical number, “Nothing Suits Me Like A Suit”, a few tantalizing glimpses into the mother’s life, and it’s a gift for the fans who had stuck around for 100 episodes.
It’s very nearly a perfect episode of television, barring one little error.
During the musical number that closes out the episode, which is performed splendidly by Neil Patrick Harris and others, there’s a brief shot of an extra who’s wearing sneakers instead of loafers.
It’s possible that it made its way into the shot by accident, as actors wearing sneakers for physically strenuous scenes is quite normal.
However, the scene still stands out.
18 Inconsistent Ages - Friends
Minor continuity errors and little anachronisms here and there are no big deal. However, when a show can’t seem to keep the ages of the characters straight, it’s a sign of some sloppy writing.
Sure, it’s not as much of a big deal with a frivolous sitcom, but Friends was a sitcom that relied heavily on making the core cast feel like people we’d know (or at the very least, we’d like to know) in real life.
In season 7, Friends makes a point that Rachel is the last member of the gang to turn 30. The episode also features flashbacks to the others’ 30th birthday.
However, we’re told in season 1 that it’s Joey who is the youngest of the group, at 25 years old, while Monica and Rachel are just above Joey at 26 years old.
Not only that, but Ross remained 29 years old through seasons 3, 4, and 5.
17 The Car Wouldn't Start - Seinfeld
Sometimes mistakes in sitcoms, movies, or any television show can lead to the best kinds of scene. The Seinfeld episode “The Parking Garage” is a great example of this.
In “The Parking Garage”, the gang spends the whole episode looking for their parked car in a parking garage. Like the previous “about nothing” episode “The Chinese Restaurant”, it’s widely considered to be a Seinfeld classic.
However, without the ultimate punchline - that once they find and hop into the car it doesn’t actually start - it’s doubtful that the episode would be as impactful as it is.
Funnily enough, tthe episode was meant to end with the gang driving off, but the car wouldn’t actually start.
It was decided that this was a far funnier ending, and so it was kept in. They were all, of course, right about this.
16 Darker Smithers - The Simpsons
Waylon Smithers made his first appearance in The Simpsons' third episode, “Homer’s Odyssey”.
As Mr. Burns’ obsessive devotee with his nerdy appearance and ruthlessly efficient demeanour, he’s as endearing as any Simpsons character.
Although characters take a while to find their way, there was one obvious, immediate difference between this Smithers and the Smithers to follow: he was dark skinned instead of yellow skinned.
His hair was also silver/grey, suggesting that the character was perhaps originally meant to be much older as well.
However, the character was never conceived as black in the first place. Instead, this was just a run-of-the-mill coloring mistake.
Since the show had quite the low budget at this point, the time and money necessary to correct the mistake was not an option.
15 Villagers Speaking English - M*A*S*H
M*A*S*H, a war sitcom, aired from 1972 to 1983, running for 11 seasons. Although it was based on the Korean War, the fact that the Vietnam War was raging on at the time no doubt ensured that M*A*S*H would frequently oscillate between the comedic and the dramatic.
It was a tightrope, for sure: even to this day, a sitcom set during a war isn’t the easiest sell.
However, this is kind of funny when you consider that M*A*S*H's finale remains the most viewed television broadcast in history, with 125 million views.
The ensemble sitcom revolved around the trials and tribulations of the personnel at the Mobile Army Surgical Hospital.
While the show was fairly historically faithful in some respects, in others, it wasn’t so much.
One such oddity being that Koreans in the villagers speak perfect English.
14 Peggy’s Mother’s Personality - King of the Hill
More down-to-earth than most animated sitcoms, King of the Hill mined a considerable amount of humor in the more conventional and mundane of situations.
Set in the fictional town of Arlen, Texas, the Hill family and the surrounding community went through their fair share of embarrassing trials and tribulations, though it was all handled with a certain amount of affection from the writers and creators, and great attention to detail and continuity.
This makes the curious case of Peggy Hill’s mother, Maddy Platter, stand out all the more.
Initially introduced in flashbacks as just an older version of Peggy Hill, she was severely retooled in a later episode, “A Rover Runs Through It”.
In this episode, she was a rancher in Montana – and much grumpier and more unforgiving than her kindly early appearances suggested.
13 Wednesday is Friday - It’s Always Sunny In Philadelphia
Blacker than midnight’s heart, It’s Always Sunny centres on a gang of demented narcissists who run a pub in South Philadelphia.
Leagues away from the aspirational nature and romance of, say, How I Met Your Mother, It’s Always Sunny is proudly vile and mean-spirited. It is also, not coincidentally, one of the funniest sitcoms of all time.
Though its brand of off-beat humour is different from many sitcoms, like most other sitcoms, it’s still prone to some hilarious oversights and errors.
One such example is in the episode “Frank’s Brother”, the opening tells us it’s Wednesday, but they receive a letter to meet Frank’s brother, Gino, on Friday at the airport.
Strangely, they leave that very day to meet Frank’s brother at the airport – and there he is, waiting for them… on a Wednesday.
12 Rachel’s Stand In - Friends
Easily one of the most popular and acclaimed sitcoms of the '90s, perhaps its only rival being Seinfeld, Friends similarly followed an ensemble and their loves and lives in New York City.
However, much unlike Seinfeld, Friends was several traces more sentimental; they most certainly hugged and learned.
The episode “The One with the Mugging” contains a blink and you’ll miss it error, though.
However, once you notice it, you’ll never be able to un-see it. During a scene, Rachel and Joey rush to Monica’s apartment.
During a back and forth between Joey and Monica, a strange brunette appears in Jennifer Aniston’s stead, just slightly out of frame, but obviously somebody who’s not Rachel.
Possibly she is a stand-in or a random crew member who wandered into the shot? It's difficult to say. Either way, it’s one heck of a blunder.
11 Visible Fog Machine - How I Met Your Mother
Like many rom-com shows, How I Met Your Mother followed the loves and lives of a group of 20-somethings in New York City.
However, the show had a neat framing device: the main character, Ted, now 50-something, was recounting the events that led him to meeting the mother of his teenaged kids in the year 2030.
The show juggled PG-13 bawdiness and warm fuzzies with remarkable aplomb, though the later seasons received some negative appraisal from fans and critics alike.
However, How I Met Your Mother still wasn’t immune to hiccups.
Look to the extremely visible fog machine in season 1 episode 11, “The Limo”, for proof of this.
10 “Goodbye, Norman” - Seinfeld
Newman is Jerry Seinfeld’s one and only nemesis. What is the origin of their enmity and disdain? It's never explained, but this only makes it funnier - well, that and Wayne Knight’s uncanny knack for playing a verbose and petty character.
Clearly Newman is something of a wordsmith like Jerry – only he makes a living as a simple mailman, perhaps resenting Jerry’s famous status.
As a partner in Kramer’s harebrained schemes, Newman’s greed leads him to some weird places and compromising places.
Such as in “The Bottle Deposit”, when Newman takes refuge at a farm. However, he is kicked out after having sleeping with the farmer’s daughter.
As he flees, she calls out “Goodbye, Norman,” which was a mistake on the actresses’ part. However, the producers were so amused they left it in.
9 The Reason for Homer's Lack of Intelligence - The Simpsons
With something like 600+ episodes of television, it’s natural that The Simpsons will circle back to the same plot points in different ways.
One of the old reliable ones is answering the question: just why is Homer so dumb?
There are contradictory reasons for this, which presents something of a continuity error.
In “Lisa The Simpson”, it’s stated that men are affected by an unfortunate Simpson gene, resulting in baldness, laziness, and stupidity.
However, in “HOMR”, an episode that followed “Lisa The Simpson” a mere three years later, we find out that Homer lodged a crayon up his brain as a young boy, resulting in his low IQ.
When it’s dislodged, his considerable intelligence is fully restored, though it proves to be more of a curse than a blessing.
8 Dale’s Suspicion - King of the Hill
One of the great running gags in King of the Hill is that paranoid conspiracy theorist Dale Gribble never, not even for a second, suspects that his wife Nancy is cheating on him with her Native American masseur John Redcorn – despite Dale’s obviously Native American “son” Joseph.
This simple joke made for some memorably uncomfortable, touching, and gut-bustingly hilarious storylines, most particularly “Of Mice and Little Green Men”.
However, judging by the pilot episode, this almost wasn’t to be.
Consider in the pilot that when Nancy scoots off for one of her “massages,” Dale says with the unmistakably cadence of suspicion, “Nancy, you’ve been going to that healer for 12 years.”
Thankfully, this suspicion was immediately dropped for subsequent episodes, with the hilarity of those storylines left fully intact.
7 Referencing The Avengers & Godzilla - M*A*S*H
Given that M*A*S*H aired 20+ years after the Korean War, there were bound to be some little anachronisms – that is, references or bits of pop culture that do not denote the exact setting of the show.
For instance, Radar is seen reading a copy of the Marvel comic book The Avengers. The Avengers weren’t even a thing until 1963, a full decade after the Korean War ended.
Also, for a few other episodes Godzilla is mentioned, but Godzilla wasn’t released until 1954.
In terms of military equipment, there’s also a picture of a Huey UH-1, a helicopter that was designed to serve for medical evacuations.
However, this helicopter wasn't actually introduced into the US military until 1959. So, while it's pretty close in terms of accuracy, it's off by a few years.
6 Hank’s “Bill” Tattoo - King of the Hill
“Be True To Your Fool” is an exceptionally touching episode of King of the Hill, as it's a great little exploration of Hank’s sometimes difficult friendship with the depressive Bill, which is a recurring theme in the series.
The premise is that when Bill gives the gang lice, they’re forced to shave their heads.
Through this, and much to Hank’s surprise, it’s revealed that Hank has a rather embarrassing tattoo on his head that simply reads, “Bill”, which was done after one drunk night years ago.
This isn’t a continuity error simply so much as it is a question of logic. How can the tattoo be a surprise to Hank after all this time?
This one’s a little odd, but overall it's definitely forgivable.
5 The Characterizations in “There’s No Disgrace Like Home” - The Simpsons
If the coloring in the early episodes were occasionally mismatched (see: “Homer’s Odyssey), then it’s also true that the characterizations would undergo some mismatching too.
This is the case with the fourth episode, “There’s No Disgrace Like Home”.
Even the premise is wildly off-base from what we know and love about The Simpsons: Homer is deeply ashamed of his family after an embarrassing company picnic and decides to enrol them in therapy.
In this episode, while Bart, Lisa, and Marge behave like dysfunctional loons, Homer acts as the sole voice of reason.
This makes this characterization mistake undeniable, given that Homer Simpson is one of the most iconic dopes in television history.
However, the most galling role-reversal of Marge and Homer’s characters has to be when Homer sells the TV to pay for their therapy session.
4 Newman’s First Appearance - Seinfeld
Season 2’s “The Revenge” is an important episode for the series. It was the first in which we got a taste of Michael Richard’s gift for physical comedy and it was the first, well, sort of appearance of Newman.
While Kramer’s scheme to get one over the laundromat was a highlight, Newman’s first appearance left something to be desired.
In this episode, he was introduced as Kramer’s clinically depressed friend.
Wayne Knight had not yet been cast in the role, so Newman remains ill-defined and voiced by Larry David (though it was to be later re-dubbed by Wayne Knight).
Despite the re-dubbing and the valiant effort to maintain some kind of continuity, it’s clear that this despondent and pathetic figure was everything the zesty and ridiculous Newman we all know and love was not.
3 Jerry Constantly Breaks Character - Seinfeld
To work on a show like Seinfeld was, as evidenced by many of the behind the scenes bloopers, joyous and enormously difficult – and for the same reason: the main cast was constantly ruining takes by exploding into laughter.
Julia Louis-Dreyfus, who played Elaine Benes, was notorious for her infectious laughter, often causing the shoot to be delayed (which is no small thing due to sitcoms being time sensitive).
However, she wasn’t the only one. The main man himself Jerry Seinfeld was prone to fits of inappropriate giggling, too.
Bryan Cranston, who played the dentist Tim Whatley for a half-dozen episodes, recently revealed an interesting fact.
“When you watch the show now, you’ll see Jerry smiling constantly. That’s the best take they had, of him not actually laughing, just smiling and trying to contain himself,” he said.
2 Historial References - M*A*S*H
In some ways, M*A*S*H commenting on the on-going Vietnam conflict was done with a degree of intelligent subtlety and emotional nuance.
As the sitcom took shape and grew in popularity, it slowly began to resemble more of a contemporary piece and less of a historical one.
This was commensurate with M*A*S*H becoming less of a sitcom and more of a drama with some comedic beats. It’s one of the oddities that still makes the show unique to this day.
There were some glaring slip ups in this regard, though.
For instance, there’s often mention of colleagues being “lost in the jungle.”
While this may sounds like something you’d hear in a movie or show based on the disputes with Vietnam, the main problem is that M*A*S*H is pointedly set during the Korean War, and there are no jungle regions in Korea.
1 Jerry’s Apartment Completely Changes - Seinfeld
Because Seinfeld wasn’t following the standard sitcom template, it took a while for the sitcom to truly find its feet.
When viewed today, the Seinfeld pilot and its very early episodes more resemble a mundane mumblecore flick than the intricately plotted works of sharp comedy the show is known for.
The most glaring difference of course is Jerry’s apartment, which has been a main fixture in the series where the characters to talk about nothin’ – and quietly set in motion plots that pay off splendidly in the last few minutes, of course.
His apartment underwent extremely minor and believable changes throughout the series, but its first appearance is so different in every way that it’s hard to reconcile this apartment and the one that featured in the episodes to follow.
Can you think of any other mistakes in iconic sitcoms that most fans didn't notice? Let us know in the comments!