Much of the humor from the animated series The Simpsons comes from the characters failing to recognize their own stupidity, being clueless when others harshly criticize them and so forth, so take this with a heavy dose of Tropes Are Not Bad.
In the Season 17 finale, "Marge and Homer Turn a Couple Play," Homer hijacks a blimp and falsely tells a baseball player that his wife loves him in order to help him win a game. Sadly the blimp crashes, and the baseball player thinks his wife is dead. Homer has to come up with an excuse. You'd Expect: Homer to say that the baseball player's wife told him to say the message since she apparently has either a fear of heights or work she has to do. Instead: Homer, being the lovable idiot jerkass he is, tells the baseball player that his wife is pooping.
Season 4's "Krusty Gets Kancelled" includes a scene where Mayor Quimby – running for re-election in a cutthroat campaign – freely admits to the press that he had looted Springfield's finances to arrange the murders of his political enemies. He diverts attention by quoting the catchphrase of ventriloquist's dummy Gabbo (the episode's Villain of the Week), "I'm a bad wittle boy!" and all is forgiven. You'd Expect: With several police officers standing nearby, for Quimby to quickly be arrested. Instead: The police do nothing as the press corps and others in the large crowd cheer wildly for Quimby. Not only is he never taken into custody, but Quimby easily wins re-election, even as more bodies begin surfacing in Springfield Harbor and nobody asks questions.
In Season 20 episode "Gone Maggie Gone," Maggie is proven to be the solution to world peace, provided she lives in a nunnery. You'd Expect: Marge to do the mature thing and allow her child to stay there, since a nunnery isn't that bad of a place to be. Plus, small price to pay for world peace, right? Besides: Nobody said that Marge (and the rest of the family by extension) couldn't live in the monastery as well, if she wanted to be with Maggie, right? Instead: Marge goes all "She's mine and no one else's" and keeps her. No explanation beyond "God would never ask anyone to give up their child for the good of the world"is given. This is fairly annoying since she learns that her children have to leave their nest in almost every episode about her. A MAJOR Flanderization of her Mama Bear attitude to be sure. Bonus Points: Homer somehow comes to the conclusion that Bart could qualify for a Replacement Goldfish. Cue to the entire church becoming hell.
In Season 20's "Homer and Lisa Exchange Cross Words," Homer makes a bet against Lisa, his own daughter, in a crossword puzzle tournament. Homer ends up winning the bet, gaining a huge load of money. You'd Expect: That Homer keeps the whole thing hidden (like keep most of the winnings in a bank or something) so no one would suspect a thing. Instead: He buys and shows off a lot of new expensive things that make it clear to everyone that something's up. This allows Lisa to get Homer to confess that he bet against her, then Lisa ends up disowning Homer as her father.
In the Season 5 Halloween episode, Homer decides on a whim to sell his soul for a doughnut, however just as he's down to the last piece, it's revealed that he keeps his soul if he doesn't finish the whole thing. You'd Expect: Homer (or really, Marge or one of the kids) to throw the doughnut away, preventing the devil from taking his soul. Instead: They keep the doughnut piece in the fridge; when Homer goes to the kitchen at night for food, the predictable happens.
In Season 8, "Lisa's Date with Density" features a subplot involving Homer engaging in tele-panhandling using an auto-dialler. Several examples of stupidity abound: First: One of the Springfield residents that falls for Homer's "Happy Dude" scam is Abe. You'd expect: For Abe to recognize his own son's voice and to either hang up or call his son and ask why Homer is asking people for money. Instead: Abe (along with Jasper, who also knows Homer) sends money. He doesn't feel any happier, however.
Late one evening, Homer has left the auto-dialler on to call residents who weren't home before, hung up or hadn't been called yet. The calls continue into the early morning hours, and it disturbs many people from their sleep … including Ned Flanders, who repeatedly gets up to answer the phone, thinking it's his mother. You'd expect: Ned to either unplug the phone or—knowing Homer's voice, since he has listened to enough of the message to decipher who it is—to go to the Simpsons' residence and request that Homer stop calling. Instead: Ned keeps the phone plugged in, certain that his mother may be trying to call him. Even better: Homer doesn't seem to get that the reason Ned's telephone (and his complaining) is disturbing the peace is probably because of his auto-dialler calling the Flanders' residence repeatedly.
In the final act, when Chief Wiggum cited Homer for his telemarketing fraud. You'd expect: A competent cop to do the same thing Wiggum did with Jimmy the Scumbag, the machine's previous owner: arrest him for fraud and, having obtained a warrant, seize the auto-dialler. Instead: Uh boy—what police incompetence here. First, neither Wiggum nor any of the other officers took the auto-dialler with them (for evidence) when Jimmy got arrested; instead, the auto-dialler is kept in the trash, allowing Homer to take it for his own scheme. Later, when Homer is charged with the same crime, Wiggum (1) shoots the machine (causing damage to evidence); (2) fails to take Homer into custody; and (3) (and most glaringly) tells him to bring the auto-dialler with him on his court date. "Otherwise, I got no case, and you go scot-free, you know," says Wiggum rather sheepishly.
Homer's court date, where… You'd expect: Homer having destroyed the evidence (since he was allowed to keep his auto-dialler), or at the very least erase the "Happy Dude" message. Instead: Homer apparently brought it to court—unseen in this episode—because he is ordered by the judge (who apparently has let him off easy) to record a new message apologizing to Springfield residents. Once he says, "I'm sorry" (in an apologetic tone), he then asks for more money through his new "Sorry Dude" scam.
In the opening gag to the Season 4 episode "Homer's Triple Bypass," a parody of COPS, Chief Wiggum and the Springfield Police Department is called to a report of numerous cattle in a yard in a residential neighborhood. The National Guard(!) is called in to provide a tank to break down the door of the suspect. You'd Expect: The officers to respond to the correct address—742 Evergreen Terrace—even if by seeing the cattle in the yard of the suspect's address. Instead: They break down the door of the neighbor's house—the one belonging to Rev. Lovejoy. As a very angry Lovejoy tries to explain to the officers that they have the wrong address, the scene shows an empty yard, before panning to the neighbor's yard, which has the cattle. The actual suspect—Snake—taunts the officers and makes his escape.
So now… You'd expect Chief Wiggum to at least be able to read a license plate and accurately describe either Snake (a well-known criminal in Springfield, whom Wiggum and/or other officers on the force have arrested several times) or at the very least his car when putting out the all-points bulletin. Instead: Wiggum fails to provide even a very vague description: "Put out an APB for a male suspect, driving a … car of some sort, heading in the direction of … you know, that place that sells chili. Suspect Is Hatless. Repeat, hatless."
In "Missionary: Impossible" from Season 11, when Homer goes overseas to engage in a missionary trip, Bart has taken over the position of "man of the house" and takes over his father's job at the Springfield Nuclear Power Plant. Mr. Burns storms into Homer's workstation to reprimand him for years of poor performance. You'd Expect: Mr. Burns—even with his advanced age and declined mental acuity—to recognize that whom he is about to scold is not Homer, given that Burns and Bart have encountered each other numerous times. Instead: Mr. Burns yells at "Homer" anyway, even as Bart tries to explain that he is not Homer. However: One of the running gags in the show is that Burns doesn't recognise or remember Homer no matter how many times they cross each other's paths. Either due to senility or because he just doesn't care. It's not as if Burns would be above child labour either.
In the Season 5 episode "Cape Feare":
Sideshow Bob, serving a prison sentence, is up for parole. You'd Expect: With numerous witnesses having testified against him and overwhelming evidence that he sent threatening letters to Bart (including several written in his own blood), the parole board to quickly and decisively deny Bob parole. Instead: Bob is paroled. Later in the episode, the Simpsons have to be placed in the Witness Protection Program. Worse: The parole board clearly sees that Bob has a tattoo saying "DIE BART DIE", and Bob claims that it's supposed to say "THE BART THE", but it's just in German, which is not entirely wrong. The parole board then consideres this a point in Bob's favour, believing that no-one who speaks German could be evil. It's as if they've never heard of this guy.
Still, Bob is able to stalk the family and eventually tracks down Bart on the Simpsons' houseboat and corners him. You'd Expect: For Bob to just simply kill Bart and complete his revenge. Instead: Bob arrogantly asks Bart if he has any last requests, giving Bart the opening he needs. Bart requests that Bob sing to him the entire score of the H.M.S. Pinafore. Bob complies … and the score is long enough to give the pilotless, drifting houseboat to run aground, knock Bob of the boat and stun him long enough for the authorities to arrest him.
In "Marge Simpson in Screaming Yellow Honkers" from Season 10, Superintendent Chalmers and Principal Skinner, in an act for the Springfield Elementary School talent show, are about to perform Who's on First?. You'd Expect: The act to be performed properly, as it had obviously been rehearsed. And nether of the two to explain the joke. Instead: Skinner botches the joke by explaining that it's not a question that Chalmers is asking, "but rather a player with the unlikely name of 'Who' is on first." Chalmers lampshades this by answering disgustedly, "Six seconds into our routine and you blew it."
Early in the series' run, a popular recurring gag was "Prank Calls to Moe," where Bart would call Moe's Tavern and ask the hapless Moe for someone whose name, when yelled out, was a double entendre. You'd Expect: Moe to quickly if not immediately catch on—since he knows Bart and thus recognizes his voice—and have the police arrest him. Instead: (1) Moe never seems to realize that it is Bart who is calling. (2) Moe falls for the joke every time (e.g., "Do I have a B.O. Problem?"). Once someone responds or the bar laughs uproariously, Moe–-rather than ending the call and immediately calling the cops—threatens the culprit with severe harm.
Possibly the most egregious lapse in Moe's intelligence comes in the Season 3 episode "Burns Verkaufen Der Kraftwerk," when (1) Moe recognizes Bart's voice (Bart having been sent to Moe's by Marge to collect Homer) and (2) Bart even announces his presence with the very words he tended to call the bar with ("Excuse me, I'm looking for …"), but instead has him sing for the bar.
In Season 13's "Homer the Moe," Bart calls Moe's when Homer is substitute bartending. You'd Expect: Homer to play along with the joke. Instead: Homer totally screws things up, not knowing what he's supposed to do. (Although one interpretation is that Homer was cleverly thwarting Bart through his playing dumb).
In Season 24's Treehouse of Horror story parodying Paranormal Activity, the family finds out that the house is being haunted by a winged demon who looks like Moe that was summoned years ago by Marge's sisters and is taking Maggie as part of Marge's deal to spare her sisters. You'd Expect: Homer to sic the demon on Patty and Selma, since they were the ones who summoned the demon who was tormenting the family (plus, they lied when they said that if Marge spared them from the demon that they would never make fun of any man Marge dated or married). Instead: Homer is forced into three-way sex with two demons and Patty and Selma get away scot-free.
"Homer's Enemy," from Season 8 — The entire premise is a "What an Idiot" trope as seen from the eyes of a newcomer employee, Frank Grimes, and his encounters with Homer. Repeatedly, Grimes tries to point out to Mr. Burns and others that Homer is a poor employee, ill-suited to the job and that his lack of qualifications, skills, ethics and attention to the job make him not only a danger to himself and his fellow employees but to Springfield (and possibly a wider region). Many situations abound: Early on: Homer is at his work console when he absent mindedly grabs a flask of radioactive acid and brings the lip up to his mouth, as if to drink it. Grimes is walking by, sees what is about to happen, and slaps it away; the substance spills onto the wall, causing it to become damaged, just as Mr. Burns is making his rounds. You'd Expect: Burns — who has supposedly hired Grimes for his skills and accomplishments — to realize that Homer was about to drink a radioactive liquid, which would possibly seriously sicken or kill him; also, for Burns to finally realize that Homer is incompetent and to fire him. Instead of recognizing Homer's incompetence, Burns is more concerned with the damage to the wall. He reprimands Grimes, demotes him and docks his pay. To be Fair Homer realises that he was being a dick towards Grimes, and tried to make amends by inviting him to a dinner in his house, apologise for his idiocy and ask for a second change You'd Expect: Grimes realizes that Homer, for all his faults, is a decent man at the core, and after the dinner, tries to reason with Homer by instructing him over what he should do and how to do his job, or more realistically, convince Homer to quit his job for the safety of all Springfield (including his family), or whatever, act like an adult and resolve his feud with Homer Instead: Grimes gets jealous over Homer's (relatively) luxurious life and only increases his anger towards him, and walks away in disgust. At same time: A jealous Grimes venting at Homer that he doesn't deserve any of his successes in front of his wife and kids. You'd Expect: Marge and the kids would defend Homer that he's only sharing his happiness with Grimes and call out on him for his jealousy. Instead: They just stood there and did nothing! Later: Grimes vents to Lenny and Carl. You'd Expect: For Lenny and Carl to concede that Homer, indeed, is a poor employee who has no business working at the facility. Instead: They tell Grimes to lighten up. In response: Grimes schemes to publicly expose Homer as a fraud by having him enter a nuclear power plant design contest ... for children (doing so by giving him a flyer that has all of the references to it being a children's contest deleted). You'd Expect: Homer to be suspicious, as he had seen the flyer at work and would be able to tell enough about the flyer he received to deduce that it is a contest he is ineligible for. Or, in the very least, for Burns or Mr. Smithers to catch Grimes in the act of his scheme and stop him. Instead: Homer takes the bait. (Note that Bart, who also is undoubtedly aware of the contest, also does not point this out to Homer.) On contest day: The contestants bring in their models to be judged ... along with Homer. You'd Expect: For Burns, who is a contest judge, to immediately realize that Homer is not a child and disqualify him. Or in the very least, for Burns to instantly recognize the other children's models as superior to Homer's simplistic design. (Although Homer showed more technical expertise (for him) in describing how his model works.) Instead: Homer is praised by Mr. Burns, before the others agree and applaud him. Homer wins first place. The end result causes Grimes to snap and run amok through the plant, complaining that Homer gets away with everything and wins everything, but he (Grimes) has nothing to show for his hard work and superior ethic and skills. At one point, he sees some high-voltage electric wires. You'd Expect: Even in his blind rage, for Grimes to at least show reason and know that touching the wires will result in electrocution and possible death. Instead: "Well, I don't need safety gloves because I'm Homer Simp--." '''ZAP!!!'''
In the Movie when Bart, Marge, Lisa, and Maggie are on the train on their way back to Springfield & the EPA are keeping track of what everyone is saying by using hidden microphones. Youd Expect: For Bart, Marge, and Lisa to keep quiet during the ride to Springfield. Instead: They run their mouths and the EPA is able to hear them! They get captured, and end up back in the dome. Way to go there, guys.
Miracle on Evergreen Terrace: at the beggining of the episode, Bart uses the "old Indian trick" (drinking water before bed) so he can look at his presents early. He ends up accidentally burning down the Christmas tree and the presents, so he takes the evidence to the backyard and buries it the snow. By the time he's finished, it's 7:01 a.m., and the family finds the tree "missing". You'd Expect: Bart to tell them the truth. It's not like he can hide what happened: someone's bound to find the tree somehow in the next few days (they do), and even if they don't, the snow will eventually melt. Instead: He generates a story about how a burglar stole the tree and all of the presents. Way to go, Bart, ultimately making the whole town think that your family scammed them later in the episode.
In the subplot of the 20th season episode "The Good, the Sad and the Drugly," Lisa looks up a website for a school project that covers what Springfield will be like 50 years in the future, and it says a Bad Future is in store. You'd Expect: Lisa to give it some deep thought and disregard the website as fraudulent (or a spoof a la The Onion), since the predictions it makes are too absurd and apocalyptic to have any basis in fact. Instead: She believes everything the website says, hook, line, and sinker.
In the Season 7 episode, "Marge Not Be Proud", Milhouse has a copy of Bonestorm, a video game Bart really wanted to play. When Bart asks Milhouse why he isn't playing it, Milhouse tells him he got tired of playing it and was more interested in playing with a cup and ball. He decides to let Bart play Bonestorm. You'd expect: Bart not to resist this chance. After all, he really wanted to play Bonestorm. He even tried renting it and once attempted to shoplift it out of peer pressure from Nelson, Jimbo, and several popular videogamemascots. But instead: Bart wants to play with Milhouse's ball and cup and fights with him over it. Not only does this cost him his chance at playing Bonestorm, but it also nearly gets him kicked out of Milhouse's house.
In the Season 25 episode, "The Man Who Grew Too Much," Lisa finds out the person who tried to kill the Simpsons, Sideshow Bob, is actually cultured and knows famous poets, authors, and artists. Bob asks Lisa to visit him again, calling her the best Simpson out of the cesspool. You'd expect: Lisa to completely reject it, or refuse politely, or visit with a bit of suspicion since this is the same person who tried to kill her family. Who knows, Bob might try to go crazy and try to kill them again. Instead: She says someone with a cultured mind and brain can't be evil. And she even said "He only tried to kill Bart." Ignoring the fact that in some episodes, Bob was trying to kill all of the Simpsons. Sure, Lisa does ask what his plan is and doesn't care until she sees her new "friend" lift an art piece that is supposed to be too heavy to lift alone. She later finds out what was his real plan, and surprise surprise, Bob tries to kill Bart and Lisa again.
In the Season 16 episode, "On a Clear Day, I Can't See My Sister", Lisa files a 20-foot restraining order against Bart, which she quickly abuses as payback for all the stuff Bart did to her. Him and Marge go to Judge Constance Harm to try and get the order repealed. You'd expect: Have the two calmly discuss with Harm what's going on and maybe she'll have the order repealed or Bart can tell Judge Harm that Lisa (the one who put the restraining order out on him in the first place) is harassing him, which, if you know anything about how restraining orders work, is grounds for having it repealed. Instead: Bart makes wisecracks at Harm's marriage life (apparently forgetting that he had to put up with her attitude in a previous episode), which causes her to extend the order to 200 feet.
In Season 17 "The Monkey Suit", Ned Flanders and Reverend Lovejoy blackmail Seymour Skinner into teaching creationism at Springfield Elementary School. Lisa brings this up at a town meeting. You'd expect: for Lisa to point out that creationism is not science, that it makes no sense to teach it at normal school when it is already taught at Sunday school or even that it is unconstitutional (as it would mean a public (government-sponsored) school favoring one or more religions against others, something that goes against the First Amendment). Instead: she just asks people to vote on choosing between creationism and evolution. Naturally, the people of Springfield choose the former, and it is soon forbidden to teach the theory of evolution at all.