A common Sitcom plot where the total Jerk Ass learns his lesson, turns sweet and benevolent — and becomes absolutely intolerable, making the other characters yearn for the original personality. Eventually the character in question will revert to normal, and the reaction will either be relief, or realization that he really is worse in his obnoxious form.
A subset of Flowers for Algernon Syndrome. This becomes worse if the cast caused this change intentionally, because Pygmalion Snap Back means the Jerk Ass returns to his jerky nature and has an ax to grind.
This can also refer to a situation where the Jerk Ass is replaced, much to the relief of the other characters... at first. It turns out that the replacement is either much worse, or is so nice that nobody can stand them. Luckily, the regular Jerk Ass will be reinstated, but nobody will ever mention this again.
Compare/contrast Teach Him Anger — trying to teach someone already nice to be tougher. This trope has a very high chance of being a Broken Aesop or Family-Unfriendly Aesop if the vice that the Jerkass cured is a genuinely harmful one; what kind of friends would WANT their acquaintance to still be an alcoholic, a religious fanatic, a bully, an incompetent worker, etc. even if it means less lulz/more irritation for them? Since Status Quo Is God, this will rarely get pointed out.
See also Better The Devil You Know, which is when the heroes want to prevent a villain from leaving, because it would result in a worse villain replacing him.
This also has some relation to Why We Are Bummed Communism Fell, where people lament the lack of a balance of power the Cold War brought.
Please be aware that examples detailing inversions of the trope shouldn't be here, take them to Took a Level in Jerkass.
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Anime and Manga
In an episode of Ranma ˝, Ranma gets hit on the head, thinks he's really a girl, and disavows fighting. Later Akane says, "Change back. I don't care if you are rude and insensitive and inconsiderate. I know I complain all the time, but sweet and innocent just isn't you."
There was also an episode where Happosai fell in love with a kindergarten teacher and decided to renounce to his, er... "evil" ways. In spite of all the fear they have of regular Happosai, Soun and Genma spend the episode trying to force him back into being a Dirty OldJerkass, stringing Ranma along for the ride. In the end, they manage to push their master far enough to succeed.
In Sayonara, Zetsubou-Sensei, during a Hot Springs Episode, the springs detoxify the mentally unbalanced class into normal, well-adjusted people. Itoshiki demands the class be returned to their disturbed selves...which they do become by the end of the episode.
He stayed at the bottom of the spring because he lost his robe when they threw him in. Last thing you see is him curled into a ball before the credits.
In volume 7 of The Wallflower, a strange woman gives Yuki a basket of mushrooms, which, once eaten, turns Sunako into a "lady". However, once they realize that she has absolutely none of the domestic kinds of skills that she had before (being able to clean, do laundry, cook, etc.), they quickly find a method to turn her back.
This was a part of the plot of Nanaka 6/17. Nenji wrestled with this dilemma when his nagging anti-social childhood friend Nanaka suffered amnesia. The amnesia regressed her personality to that of a six-year old who, while tiresome and largely dependent on Nenji, was also far more sweet and lovable than her adult self.
In the Love Hina manga, after Motoko is humiliatingly defeated by her older sister in combat, she resolves to be more feminine, and takes over most of the household chores. However, she attacks them with the same zeal and discipline that she put into her swordsmanship training, and soon makes everyone miserable. It takes an emotional breakdown and another fight with her sister (with backup from Keitaro and his cursed sword) to set things right.
In an early episode of Dr Slump, an insect crawls into the circuitry of Arale, turning her into a quiet, polite, wistful girl-bot. This freaks everybody out, so when they find out the cause and have her reset to "normal", they throw a party to celebrate.
Mega Man Star Force: The "EM meteor" in two episodes of the anime makes Omega-Xis act overly polite and gentlemanly, as well as causing him to make some... odd comments initially. Naturally, this drives Geo insane, and makes it a lot harder to actually fight for various reasons... Though this is only part of the hilarity of the two episodes, as every other EM being is affected in different ways. Hilarity Ensues.
Subverted in the Saiyuki anime; when Sanzo temporarily joined Hazel and Gato, the rest of the group sought him out to save him only because they wanted to beat the crap out of him instead. Cue Sanzo getting shot, leading to the rest of the group showing concern and trying to fight, eventually boiling down to everything going to hell from there.
Death Note: L's, and part of the audience's, reaction to Memoryless Light.
Happens to Maeda in Ai Kora, where an experimental love potion gone awry causes him to become shy and prudish instead of his usual Loveable Sex Maniac self.
Happy Lesson: In one episode, Chitose gets fed up with his "mothers'" shenanigans and kicks them out of his house, but then realizes that he is reverting to his old habits; by the end, he relents and returns the copies of his house keys that he'd confiscated.
Rurouni Kenshin presents a rather dark version of this trope. During the Kyoto saga, a lot of Kenshin's older acquaintances surface and are appalled that he's "gone soft" and try to do everything in their power to make sure they get the "old" Kenshin back. (Eventually, though, Saitou, one of these acquaintances, acknowledged that Kenshin has moved on with his life and calls off his blood feud.)
In Pani Poni Dash!, an alien takes over Himeko at one point. The alien is less annoying to have around, but soon even Becky wants Himeko back.
In Binbougami ga! if you clean a misfortune god it warps their personality, so when Momiji gets forced to bathe she turns clean, happy, extroverted, supportive and even popular. Icihko is initially freaked out and suspicious but comes to accept this new side of Momiji until it turns out that being in this form will actually kill her so she turns her back to normal by dumping her into a garbage pile. Tellingly, from this point on she begins actually using Momiji's name instead of calling her the Misfortune God.
In One Piece, three members of the Straw Hat crew, Usopp, Sanji and Franky, were disliked in their home towns. The latter two are told by the crowds at their departure that they will be missed and the come back soon. The former's pranks and lying routine are shown to be an accepted part of life in his village, to the point that some had taken to using him as an alarm and when he doesn't show up one day people are worried that they were too harsh to him the day prior.
Guy Gardner is pretty much the biggest jerk in the world in Justice League International. Until he gets clocked by Batman and got a bit of head-trauma, which resulted in a Guy who said things like "Gee, I don't want to let the guys down!" The JLI loathed Guy enough to not really wish him back to the lecherous, arrogant jerk he was, but nice!Guy kinda creeped out/annoyed most of them.
They had quite a bit of fun with this: every time Guy Gardner hit his head he would switch. Once he was under a desk, hit his head, switched back, then not 5 seconds later, after he says that he never wants to go through that again, he hits his head again.
A comic book story of The Smurfs has Papa Smurf play a prank on resident Jerk Ass Jokey to get him to stop playing his pranks on other Smurfs, by having one of his exploding surprises turn Jokey's victims into monsters. Jokey promised to Papa Smurf that he would never play a prank on any Smurf again, and so Papa Smurf restored the transformed Smurfs back to normal. Later on, however, Papa Smurf finds all his Smurfs being bored from the lack of Jokey playing his pranks on them, so he allows Jokey to play them once again.
Also in a cartoon epsiode where the Know-Nothing Know-It-All Brainy loses his essence and the other Smurfs have to bring back the annoying person that he really is.
In Twisted Toyfare Theatre, Iron Man was Nailed To The Wagon and became a sober jerk who decided to bring about the Prohibition and teamed up with villains just to make sure superheroes stop drinking. Hawkeye used some booze arrows to get Tony to start drinking again.
In the movie Shallow Hal, Jack Black gets hypnotized by Tony Robbins, gaining the ability to see the "Inner Beauty" of anyone he hadn't met before the hypnosis. He is blissfully unaware that this is happening, though. His buddy, a distraught Jason Alexander, confronts Tony Robbins and asks him to take the whammy off him. When Robbins asks, "Is that what he really wants?", Alexander replies, "I don't care what he wants! It's what I want! I want my friend back!"
Snoopy Come Home. Snoopy behaves like a prick to everyone in the film, but they all cry when he leaves. When he eventually returns, they're shocked when he continues to be a prick.
This is basically the entire plot of the Discworld short story The Sea and the Little Fishes, where Granny Weatherwax gets even with her blowhard fellow witch Mrs. Earwig by being... nice. Unnervingly so.
Also happens in one Bastard Operator from Hell story. A perfectly organised comms cupboard makes the titular character stop being a bastard. Eventually the PFY can't stand it and sabotages it to get his caustic friend back.
In the first part of the James Bond novel Thunderball, Bond is required to go for a health checkup to a special clinic. They make him stop smoking and drinking, and he starts eating weird health food. Bond eventually warms to the idea because he feels a lot better living healthily. Although M is the one who originally sent Bond to the clinic, he ends up being unnerved by the new Bond. In the end, once push comes to shove, they get their jerk back.
In Artemis Fowl: The Atlantis Complex, Holly and Foaly find themselves missing Artemis when they are instead left with his Split Personality Orion, who can't seem to distinguish reality from fiction and constantly (and obnoxiously) professes his undying love for poor Holly.
Possibly unintentional in the ending of The Tenant of Wildfell Hall: Helen's response to Gilbert (per her own instructions) learning to control and restrain his passion for her and heeding to her wishes of not taking her husband's death as the greenlight for their own relationship is, "What is wrong with you?"
In the episode "You Snooze, you Bruise" of Happy Endings, Penny tries to get Control Freak Jane, president (and near tyrant) of her condo's Home Owners Association to be nicer to the other homeowners and consider their ideas, by sleeping on it. This turns Jane into a total softy (at one point she says 'I'm being held in a chair against my will...but I'm cozy') who neglects most everything in her life, forcing Alex to stage an intervention and get her back to being, as Jane would say, aggressively helpful. This one is also a parody as the man who challenged her for president wants her back because he can't control the other tennants flouting of the rules. Like wanting a novelty gazebo on the roof, and one girl who is offering math tutoring in the building against the zoning regulations.
Wings: Roy undergoes de-jerkification with help from Joe but is back to normal by the end of the episode thanks to being partnered with Lowell during a game of Trivial Pursuit.
Malcolm in the Middle had Reese become gentle and kind, but without Reese as the "alpha-jerk" and his "even-handed bullying," the school descends into total anarachy. Seeing Stevie (whom he declared off-limits) getting bullied prompts Reese to go back to his old ways - first beating up everyone who actually deserves it.
Subversion: Malcolm himself had an episode where he bit his tongue and resisted the urge to insult everyone for being idiotic, but everyone liked this new persona, and he often got his way. Unfortunately, Malcolm developed an ulcer in only a few weeks due to his gross superiority complex and his inability to express it.
Subverted on That '70s Show, when Red had a dream about his own (empty) funeral. He decided to be kinder and socialize more, but then, after having another dream where his funeral was crowded with annoying people, he went back to his old ways.
In one of the final episodes of the show, Hyde, following a marijuana induced freak out, cleans himself up, stops doing drugs, exercises, eats healthy, and becomes generally insufferable to all of his friends. Cue a hilarious inversion of your standard drug intervention at the end where they convince him to resume smoking pot.
Also subverted on Friends, when Chandler makes a New Year's Resolution not to be sarcastic. His personality really doesn't change, but he finds that he has to snarkily comment on his friends' various foibles.
Played straight with Monica's alcoholic boyfriend Fun Bobby. He's awfully dull when reformed and sober. "There is a reason Fun Bobby is so fun."
On Red Dwarf, "Queeg", Holly is replaced by the super-strict emergency backup computer Queeg, leaving the regular cast to beg for good ol' Holly to come back. It turns out that Holly was Queeg, teaching them An Aesop.
A fandom example for series 7, where the character Rimmer left the series after the actor Chris Barrie moved on to film a Laura Croft movie. The following series, despite the Writers bringing Kochanski in as a character replacement, was not popular among fans who missed hatin the character Rimmer. They brought him back from series 9 onwards once more.
In Dexter , Quinn tells Masuka, the Lovable Sex Maniac, that the reason nobody came to his speech on his newly-published work is because of how perverted he is. As a result, Masuka starts dressing nicely and cleans up his act. This freaks out Debra immensely. It's only after they stand up for him in front of Miguel's brother that he eventually returns to his normal self, lampshadded by Debra's triumphant "And he's back!"
On the Dick Van Dyke Show, when Buddy gets himself fired, Rob and Sally get an actor to replace him, instructing the actor to be ten times worse than Buddy in his abuse to Mel (Rob and Sally are seeking specifically to invoke this trope), causing Mel to scream, "GET ME BUDDY!"
On another episode, Alan fires Mel for finally standing up to him, and Rob convinces Alan to rehire him. At first Rob isn't sure why he's sticking his neck out for Mel, who he's always found irritating. He finally decides that Mel's irritating quality is precisely what makes him good at his job.
Taken to an extreme and subverted on The Drew Carey Show when Lewis has a religious experience and fancies himself a holy man. The thing is that he's as much of a Jerkass while devout as he is normally, and in fact goes moreso, to the point of decrying official religions as not holy enough and declaring himself a new prophet. When confronted by his friends who he's been berating for their sinful ways, he shouts, "If God doesn't like it, he can tell me so!" ...whereupon he's struck by lightning. "Could have been just coincidence!" The next two direct strikes convince him, though, to the point that he breaks down and says "Fine! Fine, I'll smoke, I'll drink, I'll masturbate! If someone will help me, I'll do all three at once!"
In Titus, Papa Titus decides to give up drinking. Sober, he realizes what a horrible father he's been and spends all his time crying, never leaving the house, he ignores attractive women and almost loses his job as a salesman because he stops having fun with his clients. The other characters goad him into starting to drink again, and he does, but then gets angry at the things they said and starts playing mindgames to get revenge.
In the US version of The Office, Dwight is fired and replaced by Andy, who is just as annoying and doesn't even have Dwight's various eccentricities that made him so much fun to wind up. Jim: "I miss Dwight. Congratulations universe, you win." A bit of a twist as when Dwight returns Andy stays in the office, becoming a little more likable in the process.
Subverted in an episode of House in which House tricks the other doctors into thinking he has syphilis, which can cause personality changes. The rest of the cast then tries to treat him with penicillin, thinking that the syphilis is what made him a Dr. Jerk - as if the syphilis itself isn't enough of a reason. He, then, in order to mess around with them, pretends to be nicer, but also purposefully acts like a way more crappy doctor. Cue the chorus.
There was also that time House switched to methadone, and while he was happier and pain-free, he ended up convincing himself that his diagnostic skills are seriously compromised as a result of being nice (he agrees to a "pointless MRI" to please the parents because he doesn't feel like being a jerk to them; resulting in the dye almost killing the dehydrated boy who otherwise would have been completely fine), and he's back on Vicodin by the end.
Night Court performed an extended version of this trope during most of its 8th season and the early part of its 9th season with a subplot where Casanova Wannabe Dan Fielding became a virtuous do-gooder after being placed in charge of a charitable organization. Even after he left the charity job behind, Dan still remained nice, thoughtful and respectful to women... until he was slapped by a woman who had hoped to enjoy the pleasures of the old Dan. The slap awakened the long-repressed lecherous urges of the Old Dan who proceeded to give the woman what she wanted... and then some.
There was also once a flashback scene where it's revealed that Dan (real name Reinhold) was actually a prudish gentleman, until a sophisticated (but slutty) Southern Belle takes his virginity, resulting in his subsequent chicanery.
Used in How I Met Your Mother when Barney tries to sleep with Robin again: after Lily points out that Nice Guy Ted dated Robin for a year, Barney spent the whole dinner being nice and polite, even ignoring other women. This had the opposite effect, freaking Robin out and she spent half the dinner trying to get him 'act like Barney' again.
However, it's averted for the series as a whole. During the course of the show, Barney has become increasingly mature and sensitive.
Father Ted - episode New Jack City. Smelly drunk Father Jack develops Hairy Hand Syndrome and is shipped off to an old priests home. His replacement is a terrible bastard which causes Ted and Dougal to mount a rescue mission. With hilarious results!
Dinosaurs - In one episode, Baby Sinclair is named king of the dinosaurs and taken away to 'fulfill his destiny'. While the entire family is noticeably upset, Earl especially has trouble returning to a life without Baby to say "Not da mama!" and hit him with a frying pan. Robbie tries to substitute, but just can't do it right.
In an episode of Stargate Atlantis, McKay has a alternate reality counterpart show up. The entire cast seems to get along with the new Rodney Rod (even his sister), until he returns to his reality. They invite the original over to their table in the mess hall and tell him the alternate was kinda creepy and he would never be replaced.
Played with later in the episode Vegas. It is set in the alternate Rodney's universe. Shepard has the same personality, but as a detective his personality causes him problems. Of course, alternate Rodney knows he has potential...
Frasier once got rid of his agent Bebe, an extremely successful but comically amoral Heroic Comedic Sociopath often compared by the other characters to Satan, in favor of a nice, mellow and family-oriented agent who turned out to be utterly incompetent. In the end, he had to swallow his pride, and his scruples, and ask Bebe to come back and clean up the mess his new agent made of things. She did so with gusto, and he learned better than to ask how (murder and blackmail may or may not have been involved).
Also in the episode "Love Bites Dog", jerkass and intense womanizer Bulldog steals a date that Frasier is on from right under his nose. A few days later, Frasier and Roz find out that Bulldog has fallen in love with this woman. They are both shocked at his changing personality, particularly Roz. However, Bulldog is heartbroken when she dumps him on the phone right before his sport's show. Afterwards he cries on the air and leaves the station, resulting in Frasier filling in for him. Feeling out of place, Frasier realizes that he has to revert Bulldog back to his usual self and quickly.
This is done in Entourage when they fired Ari Gold.
Done seriously in NCIS where after Kate dies Gibbs becomes subdued and not nearly as much of a jerk, freaking out the rest of the team.
Promptly subverted when McGee timidly pipes up that he kinda likes the new Gibbs . . . only to be glared into submission by his teammates.
This also happens during his "retirement" phase, when he came back from Mexico with a mustache. Shaving the mustache marked Gibbs' return to normal.
And more recently, Tony grows unexpectedly professional for an episode, which gets all the other characters wondering if this is an elaborate prank or if there's something seriously wrong. It's the latter.
At the start of Mystery Science Theater 3000 episode 424, Joel has installed "protocol modules" in Crow and Tom to make them nicer. While he notes they're easier to deal with, their incessant praise of him leaves him "kind of hollow". He removes the modules just prior to the Invention Exchange, with Tom immediately criticizing Joel's hygiene.
Meet The Browns: When Mr. Brown got hit on the head his whole personality changed: suits and sweaters instead of loud 70's clothing, courteous and kind, instead of whiny and rude, and (for some reason) speaking in a British accent. At first family and friends enjoyed the new Mr. Brown, but when he began to be brutally honest about their actions and character, they decided that the original Mr. Brown wasn't that bad after all.
In The West Wing, whenever Toby Ziegler isn't acting like like the abrasive, self-righteous, pompous and short-tempered jerk he usually is, people get worried fast. Of course, the nature of working in the White House means that the other characters either don't have time or don't have to worry about whether he'll switch back, because something inevitably comes up to ruin his mood anyway.
Happens twice to Sally Smedley on Drop the Dead Donkey. The first time, in Series Two, the conversion is religious after the death of her grandmother, and increases in intensity until she ends up being jerked out of it two or three episodes later by a perverted evangelist (just as George approaches her for spiritual guidance on his marriage breaking down). The other characters attempt to shock her out of it. The second time, later on in the 1990s, she falls pregnant from a one-night-stand, decides to keep the baby, gets broody, and then miscarries, all in the space of two or three episodes. The others decide to be a bit more sympathetic to her this time round, only for her to decide the day after the grief over the miscarriage that she has given up feeling anything whatsoever and is happy to go back to being a cold-hearted slapper.
In Waiting For God, Diana finally drives the odious Bayview manager Harvey Baines into an asylum or so everyone thought; he was just faking it, and while everyone hates Harvey, they are still mad at her for doing it.
On one Monk episode, Monk takes medication for his OCD, and it causes him to lose his great detective skills.
An episode of Lucky Louie has Kim getting mad at Louie because he never helps out around the house, complains when she asks him to, and doesn't seem to care about his appearance. The next day she wakes up to find that he's dressed very nicely, has gotten Lucy ready for school, made breakfast, and is making an obviously concerted effort to be cheerful. She finds it creepy and tells him to stop.
On Parks and Recreation, when Tammy 1 returns and gets Ron back under her thumb, he turns into a friendly, hardworking, clean-shaven version of himself. His friends don't even briefly entertain the thought of keeping this Ron — he terrifies them. When he starts expressing trust for the government, Leslie actually slaps him. (She herself loves the government, but coming from Ron, this is mirror-universe stuff.)
Tom loves fancy status-symbol products and always focuses on image over substance, so naturally, his tendency towards overspending leads him to run his first company into the ground. He decides to be more serious with his next venture, but takes it way too far, forcing his friends to point out that both him and his new clothing store are no fun at all.
On the WKR Pin Cincinnati episode Chances, Herb Tarlek is tutored to make him less offensive, abandoning his usual loud plaid suits and obnoxious salesman persona. However, the only clients Herb was ever successful with were also loud, obnoxious and disreputable and don't like the "normal" Herb. Herb reverts to his former persona to keep his clients.
In Everybody Hates Chris, our eponymous hero HAS to do this to his bully Caruso when Caruso gets a (painful) lesson in humility. The word HAS is used because Chris is a Cosmic Plaything and in losing Caruso as a bully, he gets many more as a result. He lampshades it heavily:
(Older Chris narrating) "Caruso was feared above all else. Kids feared him yet wanted to be like him. When he lost that power, the school went into chaos as kids tried to gain power and also a piece of me. (Mob of kids surround Chris)"
(at a fixed fight to help Caruso)
Chris: (walks away)
Greg: "Where you going man? Don't you wanna see the end of the fight?"
Doc Martin: After Martin resigns to go to London at the end of season 4 he is replaced by the lovely, sweet, and patient Dr Dibbs. She's so bad at the job that it's a relief to get grumpy old Martin back.
Played very straight in the third season of Angel. Wesley tortures a woman for information on Angelus' whereabouts and tells Faith that this is the sort of thing she should be doing, because if she's to be a match for Angelus, she needs to be the Faith who brutally tortured him two seasons earlier.
In Bloom County, Steve Dallas was a Casanova WannabeJerkassStrawman conservative who, somewhere around the last year of the strip's run, had his brain reversed by aliens, turning him into a bleeding heart liberal feminist nice guy with a perm. He remained this way for months with no indication this wasn't just a permanent change. In the series denouement, however, his longtime girlfriend dumped him, and in his despair he put his sunglasses back on, and instantly returned to the iconic Steve Dallas, and has remained so in all of the strip's spinoffs.
Although it was subverted in that the cast seemed to like the kinder Steve, with Milo actively trying to discourage him putting back on his sunglasses and screaming "HE'S BACK!" in an absolute panic when Steve goes through with it.
In a 1987 story arc, Garfield, of the strip of the same name, loses his memory, becoming a much more "normal" cat. His owner and the other cast members attempt, and succeed in restoring his memory.
Jon: You just have to restore Garfield's memory, doc. He doesn't beat up on Odie. He doesn't claw the furniture. He's not lazy and obnoxious.
Liz: Are you sure you want me to do this?
Jon: Come to think of it...
A similar situation occurs in an early episode of the TV show, Garfield and Friends, but taken to a slightly more extreme degree in that Garfield becomes the polar opposite of his normal self.
Subverted in Pearls Before Swine. After Rat "un-died" once, Goat and Zebra already came to the conclusion that Pig was the main character of the strip and they didn't really miss him at all.
Inverted with "Stone Cold" Steve Austin concerning his case, though Austin's always a jerk no matter his current alignment. When Austin turned heel in 2001 after WrestleMania X-Seven, his subsequent Badass Decay and sucking up to Vince rose to the point that even Vince wanted the old Stone Cold back. When Austin finally turned face again after the InVasion angle was over, the fans went nuts.
Ignoring issues of Badass Decay, it's become apparent that some wrestlers are just better at being heels. Much like how some actors are simply better at being villains than heroes, some wrestlers are better at getting people to boo them than cheer them. Unfortunately, people behind the scenes confuse Love to Hate with simply Love and decide to turn them. Forcing a person whose specialty is being a smug, arrogant, charismatic Jerk Ass to suddenly try and be a smiling good guy has left many prominent careers in its wake.
If Jim Rome is thoroughly disgusted with the attitudes of the callers and e-mailers during a particular show, he will threaten to switch the format to "Nice Radio", a.k.a. "The Garden" (in contrast to "The Jungle"). During "Nice Radio", all smack talk is abolished, and a couple of segments of Jim speaking nothing but flowery praise is usually enough to bring the listeners back in line.
Ghost left for a while saying he wouldn't come back unless the trolls doxxed Celtic Brony. It took them a day.
The rival characters in the first two generations of Pokémon were total jerks; from third generation onward, we're given friendly, helpful, BORING replacements.
In Star Wars: Knights of the Old Republic II, the player can acquire an item called "HK Protocol Pacifist Package", which can turn the ruthless, sadistic and bloodlusting assassin droid HK-47 into an unbearably polite pacifist. The player character then hastily removes the package, much to the droid's gratitude.
In Sam and Max: Bright Side of the Moon, this is Sam's reaction when the villain removes Max's anger, gluttony, and laziness, leaving the original Max a blissed-out goody-goody instead of the comically-sociopathic rabbity-thing Sam knows and loves.
In The Order of the Stick#58, Vaarsuvius magically increases Belkar's wisdom to enable him to use a healing spell scroll. With his increased wisdom, Belkar regrets his violent ways - until the wisdom increase is dispelled to bring back the old Heroic Comedic Sociopath, since they need him for a fight.
A common occurrence in PvP, usually related to Brent making the effort to be less cynical and unfeeling. The other characters appreciate it at first, but then realize they don't like it; during a period where Brent gave up coffee and became nicer for it, Cole asked Skull if he was happy that Brent no longer treated him poorly. Skull responded, "No, I just want him to be Brent."
Averted in Shortpacked!. The way to change the jerk into a nice guy is found and this weakness is used to blackmail the jerk into a relationship, as a jerk.
In one storyarc of Ctrl+Alt+Del, Ethan gets electrocuted by a telephone wire while trying to "unclog the internets". As a result, he now no longer has unhealthy interest for video games and instead wants to make tea and read books. The problem is that New!Ethan is better in every way than Old!Ethan. His friends however are driven mad by the wackiness withdrawal and both become like Old!Ethan.
Ultra Fast Pony. Discord warps the personalities of Twilight's five friends—but unlike canon, he does this by inverting their main vices rather than their virtues. In spite of their being allegedly improved, Twilight notes that "You guys have turned into even bigger jerks than you usually are!" and their attempts to help provoke a "Stop Helping Me!" response. Even the Elements Of Harmony agree with Twilight, as the magic friendship laser doesn't work until Twilight reverts her friends back to normal.
Kim Possible: Drakken in "Bad Boy". Ron has this attitude towards Shego in "Stop Team Go".
Totally Spies!: “Super Agent Much?": Alex and Sam become suspicious when Clover develops super abilities. 
This happened to Bender on Futurama when he found religion in "Hell Is Other Robots", though it had more to do with Bender being obnoxious in entirely other ways (like multi-hour sermons in stuffy, un-air conditioned rooms)—and to a lesser extent, Farnsworth in "Bendless Love", when Bender bent his spine so he continually faced upwards. In "How Hermes Requisitioned His Groove Back", Bender's personality is downloaded and sent to the Central Bureaucracy. This reverts Bender to a simple "insert girder, bend girder" mode. When it is noted that Bender is now helpful and polite, everyone decides to get their jerk back. They even lampshade it by not being able to rationalize why they should.
Family Guy: It happened to Peter Griffin about a dozen times, e.g. when he stopped being a couch potato, when he stopped being a chauvinist, when he tried to learn how to act sophisticated (though in that one, he just became a very different kind of jerk), etc. It would seem that Lois has never heard the expression Be Careful What You Wish For. Given that when he has an excuse to act like more of a jackass he does (such as in "Petarded", when he finds out people will excuse him anything after he's diagnosed as mentally incompetent).
Another episode showed that after becoming physically fit and generally pretty, he turned into an ever bigger jerk.
It also happens to Stewie in the episode "Stewie B. Goode", when a near-death experience and a vision of hell scares him into being 'nice'. However, this makes Stewie look like a complete tool until Brian eventually snaps him out of it.
Though an unintentional example, again with Peter, after he's more of a moron than usual Lois calls him an idiot. This prompts Peter to start traveling to Chicago and New York to "broaden his horizons". When he gets back he's significantly more intelligent and Lois likes this at first, but Peter then becomes obsessed with making everybody around him smart and makes everybody else feel dumb in comparison. As per this trope, Lois gets annoyed by this and fixes this by sending Peter to the dumbest city in America (Tucson, Arizona) and he's back to normal.
Long before it happened to Peter, it happened with Fred in an episode of The Flintstones. Being hit on the head turned him into a polite, articulate gentleman... Who everyone found even more obnoxious than before. Barney suggested knocking him on the head again to try to turn him back to normal, but neither he, Wilma, or Betty could make themselves do that; but they managed to trick him into doing it to himself.
In another episode this happens to Miriam when Bob injures his back and she takes over the Beeper Emporium. Bob stays on the couch glued to the soap operas while Mirium ends up staying late at the Emporium every night, too busy to pay Helga any attention.
Duck Dodgers when he got run through the "purifier" machine. (It took a day or two.)
Not to mention the episode that he quits the Protectorate for a glamorous job in the family restaurant sector.
And finally, the episode where the Martian Commander removes Dodgers' brain to study why he's such a "genius", swapping in an artificial brain in the meantime. Dodgers ends up far more competent and heroic with the replacement brain and defeats the Commander easily, retrieving his real brain. At the end of the episode, Cadet realizes that this will just turn Dodgers into a useless Jerk Ass again, but can only remark "It was fun while it lasted..."
A week of being unable to talk taught Homer to listen in The Simpsons episode "Jaws Wired Shut", after which he found the joys of a polite, sedate existence. Marge was so used to his shenanigans, however, that weeks of dormancy drove her insane.
A double example from a different episode, "Home Away from Homer": Flanders moves to ultra-nice Humbleton, PA, and a Jerk Ass jock moves into Flanders's old house, next to the Simpsons. Both Ned and Homer realize how good they had it before and everything goes back to normal.
This also occurs at least twice with Principal Skinner, of the "gets replaced by a worse replacement" variety:
The first time, in "Sweet Seymour Skinner's Baadasssss Song", he's fired and replaced with Ned Flanders, who refuses to punish anyone, which causes the school to descend into anarchy.
The second time, in "The Principal and the Pauper" his replacement is voiced by Martin Sheen, they subvert (via exaggeration) Status Quo Is God by running the alt-Skinner out of town on a rail, and having Judge Snyder solemnly pronounce Let Us Never Speak of This Again under threat of torture. Literally, all of the above. Ironically, he was a rather nice and reasonable fellow who was exiled simply by... not being Skinner. I mean, he was Seymour Skinner, just not the Seymour Skinner that Springfield was used to.
From "Weekend At Burnsie's":
Marge: Homer, you don't need drugs anymore. Your eyes are all better.
Lisa: I want my old dad back. The one who was yelling all the time, and ... you know, I'm not really sure what I want.
In one Tom and Jerry short, Tom is hit over the head with a broom and thinks he is a mouse. He immediately becomes totally harmless and takes a highly annoying liking to Jerry, who cannot stand this and spends the whole episode trying to turn Tom back into his arch-enemy.
Played mostly straight in Daria: in "Quinn the Brain", when Quinn happens more or less by accident to get a reputation as 'a brain' (while still remaining popular), Daria realizes that this is impinging on her self-image. She proceeds to do a turn-about on Quinn by dressing fashionably and pretending to go out on a date with The Three Js, causing Quinn to ditch the beret and black sweater and go back to the Fashion Club.
Later in the series, it's established that Quinn really is intelligent and she finally lets go of her fear of embracing it. By that point, Daria has gotten over enough of her own personal issues to actually be supportive of her.
The Tick is locked up, leaving a lunatic to defend The City in his place. The villains are glad to be rid of their nemesis at first, but quickly realize that the new Tick is much worse. Chairface Chippendale organizes the villains saying, "we've got to rescue the Blue Tick, who is also mad, but in a much more goal-oriented way."
Hi Hi Puffy AmiYumi uses this trope in the short "Bad Manager" in which the girls have their jerky manager Kaz loses a bet and wind up with a new manager who treats them quite well and provides them with all manner of luxury. In the end the discover Kaz, down on his luck and they decide to try and get him back because he's "family". Standard use of Snapback.
In the episode "Changing Gears" of the original Transformers cartoon, the Decepticons remove a critical component they need for their Weapon Of The Week from the Autobot Gears, changing him from his usual grumpy, complaining self into being a lot nicer. The other Autobots react negatively to this:
Ironhide: What did you do to Gears, you monster?! You turned him... nice!
Nearly inverted at the end of the episode, before Optimus Prime replaces the component anyway, and Gears begins grumbling again only to be left behind by the other Autobots.:
Trailbreaker: Well, we took a vote and... we decided we like Gears the way he is now.
In the South Park episode "Tsst!", Cartman is trained by the Dog Whisperer into a well-adjusted, polite, and friendly little boy. After being rejected by the dog whisperer, his mother then realizes that she can no longer treat her son like a "best friend," thus robbing her of her ONLY friend. A little bribery, however, reverts him back to normal.
In "Timmy 2000", all the boys take Ritalin and become dull and attentive. Mr. Garrison misses their crude behavior and Chef helps them return to normal with help from an "antidote" drug named "Ritalout".
Averted when Cartman's goateed "evil" mirror self showed up, who, being the "evil" version of Cartman, was extremely nice and thoughtful; Stan and Kyle like him so much better than Cartman that they actively try to send their universe's Cartman back to the mirror universe instead. it didn't work.
In "South Park Is Gay" the women of South Park are at first pleased to see how neat and presentable their husbands become after catching the latest metrosexual fad, but soon the effimancy, vanity and general uselessness of males starts grating on their nerves and they are forced to take the only appropriate action in such situation: murder the cast of the gay show that started the fad.
An episode of Teenage Mutant Ninja Turtles had this happen to resident Jerk Ass Raphael, when he accidentally blasted himself with a "Personality Alterator" ray, set to "Very Nice". His friends were happy at first, until they discovered that he was so nice he'd even help the criminals they were trying to capture. The episode's villain also used the ray to make the city's police and guards similarly docile and captures the Turtles with no effort. The Turtles finally get Raphael back to Jerk Ass by setting the ray to "Very Nasty" and getting him to shoot himself with it.
That wasn't the first time it was used either. In an earlier episode Leonardo decides that everyone needs to train harder. The other turtles get tired of working so much and use the Personality Alterator to make Leonardo into a fun loving, laid back guy. He plays annoying pranks on the others, and doesn't care about fighting crime. Not only are they sick of him but they need the old Leonardo to help them beat the villain of the week.
An episode of Beverly Hills Teens had Alpha Bitch Bianca trying to be nicer to people. He chaffeur, Wilshire didn't like the change, preferring her old self.
One episode of Tiny Toon Adventures had Buster, Plucky and Hamton trying to fix Dizzy Devil by combining their personalities and putting them in him using a machine, it works, the new Dizzy is polite, intelligent and good natured, but it is revealed that the old Dizzy was very popular with girls and said girls are rather unhappy with the new Dizzy.
In an episode of The Penguins of Madagascar, King Julian is led to believe that the eclipse is caused by him being a jerk to everyone so he decides to be nice but he becomes very annoying trying to help everyone. An annoyed group of penguins and a made up "sign from the sky spirits" later he's back to normal.
Or when Dexter made Dee Dee much smarter so she would stop fooling around and start helping him with experiments, but she turned out to be more competent then him, so jealous Dexter reverted her back.
An inversion happens when following another rant about her being stupid Dee Dee in return pitifully chastises Dexter for spending his youth alone in his boring lab and not knowing how to have fun. Devastated Dexter pleads his sister to teach him "the way of Dee Dee". She agrees, but the results are catastrophic - reworked Dexter proves to be even more erratic and destructive then Dee-Dee herself. She smacks him back into his right mind.
In The Weekenders episode "Sense and Sensitivity", Lor's friends finally get fed up with her jerkish behavior. She spends the rest of the episode going out of her way to be kind and thoughtful, which drives her friends crazy and makes them wish for the old Lor back. And the catalyst that starts all this? Lor losing a basketball game by being a ball-hog. They're worried that she might start passing the ball... to the other team.
Although in an unusual moment of Fridge Brilliance for a kid's show Lor does mellow out in later seasons, showing that she did work hard to become nicer without going overboard.
In an episode of Dave the Barbarian, Dave's little sister Fang, known for being the single most violent, fearsome being in all the land despite being pint sized, undergoes a transformation that makes her much more sedate and ladylike. Dave and his older sister Candy appreciate this greatly for a while, but then the kingdom is threatened by giant bugs. Fang, who the bugs are terrified of and would flee from on sight, refuses to go into battle and instead settles to make clothing for the beetles, as she's been putting clothes on every animal she possibly can. Dave and Candy try to make her snap back to her usual self, but fail until Fang sees both her siblings in danger and promptly goes back to her normal homicidal rage monster self to protect them.
Even more so in the episode where she was kicked out of B.R.A.T. Timmy Turner called her out as not being nice and therefore having no friends. She take it to the heart by becoming a Clingy Jealous Girl towards Timmy and forcefully turning him into her girlfriend-replacement. Timmy had apparently no choice but making Vicky hate him again.
This has happened a number of times in SpongeBob SquarePants with numerous characters, sometimes as a whole episode plot and sometimes as a single sub-portion of the overarching story. A few examples are when Squidward was electrocuted by his own electric fence and developed a personality very similar to that of Spongebob (at the end he was returned to normal by another electrocution, which also struck Spongebob and Patrick, turning them both into Squidward personality clones), a time when SpongeBob tried to become "normal" and lost everything unique about his personality, and when Patrick's brain was accidentally replaced with brain coral after an accident, turning him into a super-genius who does not understand the concept of fun and is too smart even to be liked by Gadgeteer Genius Sandy. That one ends up being Flowers for Algernon Syndrome, with Patrick using his newfound genius to mathematically determine his actual brain's location in the brain coral fields where he lost it so he can become his old self again.
A minor variation also came when Squidward, after yet another disastrous run-in with SpongeBob and a door, recovers to find himself suddenly quite handsome. He enjoys the new attention it brings him, only to then find his admirers refuse to ever let him alone. He ends up begging SpongeBob to bash him with the door again.
In an episode of The Angry Beavers, Norbert suffers from "Damnesia" (where you forget everything except what damnesia is) and, horrified to see the way he treats Daggett in home videos, resolves to become the perfect brother. Daggett enjoys it initially, but ultimately wants his old brother back.
In Aaahh!!! Real Monsters when the Gromble is sacked by the Superintendent the students go insane from the Superintendent's insultingly simplistic instructions, as they are forced to read textbooks years below their skill level and are expressly forbidden from performing fieldwork. They end up seeking out the Gromble and begging him to give them more intellectually stimulating assignments and he starts leading them on secret midnight scare raids. When status quo returns at the end of the episode the main characters express relief as they listen to the Gromble's sadistic rantings, which normally leave them frightened.
Happens on Ed, Edd n Eddy where Edd tries to reform the other two, and eventually realizes they were better as they were before, but it turns out they were just playing him the whole time and hadn't really changed.
In the Adventure Time episode "Donny", Finn and Jake stop a grass ogre named Donny from beating up a town of house people and reform him. Then Finn discovers that the ogre's jerkiness was the only thing keeping a pack of whywolves from attacking the house people (by producing a gas named "obnoxygen" that poisons them). Now they have to make Donny a jerk again to save the house people.
This is forced onto Johnny Test when his sisters try to separate his bad "juju" for wrecking their lab. Johnny turns into an obedient, cheerful, and hug-happy shell of his former self. Unfortunately the bad juju ends up turning into a destructive Evil Knockoff and his sisters get sick of all the annoying hugs, prompting the yearning for the normal Johnny.
The Generator Rex episode "Robo Bobo" deals with the second version of the trope: Bobo decides to take a break and puts a robotic duplicate in his place, which unlike the original, is considerate and rule-abiding. Rex, having grown used to Bobo (and annoyed by how much of a goody-two-shoes his double is), slowly reprograms the robot to be more like the real ape. In the end, it ends up learning too well.
On Phineas and Ferb, This happens to Buford when he loses his goldfish in "Voyage To The Bottom Of Buford."
On Arthur, This happens to Binky occasionally, as well as to Francine in "Meek For A Week."
On an episode of Garfield and Friends, Garfield is hit on the head and gets amnesia. He becoms a sweet, polite, cat who only eats healthy food and wouldn't dream of kicking Odie off the table Jon and Odie are worried and take him to the vet. The vet wonders why they want to restore Garfield to normal. By the end of the episode a second hit has him back to normal. Garfield promptly eats everything in sight and kicks Odie off the table. Jon and Odie couldn't be happier.
Also happens in a U.S. Acres segment. Orson has is tired of Roy's insults and has him fired. So Wade invokes this trope by hiring his annoying cousin Fred to replace Roy. After a few minutes of his insults Orson is yelling to get Roy back.
In Life With Louie Jen Glen is Jerk Ass and Large Ham so big that the entire town fears her. In one episode she loses her voice and it quickly turns out to have strange effects on the community, because many people starts acting like they have no purpose or turn into their certain opposites - Andy, the town's second Large Ham, even becomes calm and forgets about the war (leading to Alternate Character Interpretation that he may be a Shell-Shocked Veteran and that it's Jen's loud and angry behavior that constantly remainds him about some traumatic experiences from the war). The entire town works in the end to raise money for her operation.
Totally averted in the Dan Vs. episode "Dan Vs. Dan". When Dan's response to his identity thief is apparently to give up and reinvent himself as Nice Guy Biff, Chris is overjoyed that he has two nice friends instead of one Jerkass friend. Elise thinks the whole thing is an act and of course she's right. After the fake Dan gets arrested because the real Dan missed a court date, Dan promptly goes back to being a Jerkass. Chris falls to his knees weeping over the loss of his two new friends (especially because fake Dan baked him pie).
Archer gets one with Malory. In a drunken fit, she sends out a burn notice on her son, and, once she sobers up, is horrified at what she does and begins moping endlessly. Ray and Cheryl remark that they liked her better when she was mean.
Happens on The Proud Family after Lacienega loses her confidence after getting ridiculed for her big feet and Penny wanting her to be back to being herself again.
Done in Archie's Weird Mysteries. Reggie is kidnapped by aliens who create a clone to replace him so nobody will notice. However, they literally ask him what he is like, and thanks to Reggie's raging ego, he describes himself as a literal saint. Suffice to say, Archie and the gang notice the difference immediately and hate the "new" Reggie. Bonus points that the real Reggie actually beats the clone in a a nice contest, by telling the clone that if it really was the nicest it would let him win, which makes it punch him in the face to throw the contest.
This happens to the title character of the cartoon version of Beetlejuice, after he's sent to a rehabilitation facility for a prank that goes to far. He becomes a polite, decent person, but everyone finds him mind-numbingly boring. The Mad Scientist Dr. Prankenstein tries several treatments to try to return him to his normal self so he can save Lydia, and after all of them fail, he uses something he's saved for an emergency - the Pranken-beetle. It works like a charm.
Ask anyone who has a friend who suddenly got very heavily into religion. Nine times out of ten they'll more or less reference this trope.
Naturally the same could be said for anyone with a friend who suddenly got very heavily into militant atheism, militant feminism, or any other dogmatic philosophy.
There is an Arabic proverb: "He left us, and we rejoiced. But then an even more obnoxious person arrived."
Sadly, this can come into play in abusive relationships, especially when it's the circumstance where two people are abusing each other. Though calling an abuser a jerk is sort of an understatement.
Rivalries in general can be like this, if something should inspire change in one person.
Steve Jobs was kicked out of Apple in 1985. By 1997, however, Apple actually wanted him back! Of course, Jobs had managed to get his ego under more control in those 12 years. That, and Gil Amelio's mind-boggling incompetence found people preferring Steve. Sure, Jobs was a Jerkass (even his authorized biography pretty much says so up front), but he was a Jerkass who actually had vision and got things done! And now that he's gone for good...
Certain types of brain injury can cause personality changes. Loved ones should be concerned, even if the change seems for the better.
During February 2011, roadside signs started popping up that depicted former president George W. Bush waving next to the text "Miss Me Yet?" The implication being made by whoever put these signs up seems to be that Bush was bad, but Obama's worse. So now we miss our old less worse president.