You Have to Believe Me

""Our wives, our children, everyone! They're here already! You're next! You're next!""

- Dr. Miles Bennell, Invasion of the Body Snatchers, trying to convince random people that he's not crazy

Say a character finds out about a paranormal phenomenon, or a sinister conspiracy. There wouldn't be much of a plot left if they could just call the police and let them take care of it.

In these cases, heroes will simply talk like homeless paranoid schizophrenics.
 * 1) They will continually repeat a bizarre claim in a panicked voice
 * 2) They will avoid mentioning what led them to believe it in the first place
 * 3) They will never consider sticking to the provable parts of the story for the time being
 * 4) Most important, they will be stunned and angry that anyone would find their claim implausible, regardless of how implausible it would be even if they weren't completely flushing any credibility they might otherwise have down the toilet in their method of persuasion.

They may then start wondering out loud if the disbeliever is "in on it." And if anyone tries to calm them down, rather than taking a few deep breaths, sitting down for a moment and coming back to the problem in a calmer fashion they will immediately violently lash out, thus prompting the immediate summoning of the nearest security guards to have them ejected from the premises.

And then they wonder why no one believes them.

What's more, this will give the heroes a reputation for Crying Wolf, making it even harder for them to get anyone to believe them. Of course, the senseless deaths of the skeptics is often seen as a karmic comeuppance in favor of the hero, even if it was the heroes' fault they aren't believed in the first place.

The other side of this trope is that, if the person making the claim sounds crazy, the listener will dismiss them to the point of going out of their way to dismiss them, no matter how simple it would be to investigate. When someone is screaming "", you can be assured that the listener will not turn around; they will, in fact, stubbornly and strenuously refuse to turn around.

A possible cause of any disbelief towards the explanation of "aliens did it" in a continuity where aliens and alien invasion are not only known and documented, but semi-regular events. (Of course, this may be because some people are just stubbornly, willfully stupid, but hey.)

A kind of Poor Communication Kills. See It Was Here, I Swear, Cassandra Truth, Properly Paranoid, Not Helping Your Case and You Can See That, Right? Sometimes, this overlaps with Clap Your Hands If You Believe — the character must convince someone to believe because belief itself is necessary to save the day.

Anime and Manga

 * Three By Three Eyes
 * Played straight with Yakumo, who tries to tell the amnesiac Pai that she's in danger, she's not human and she's actually the last survivor of an immortal race. He says he doesn't want to 'sugar-coat' it for her, but he then actually acts surprised and angry when Pai thinks he's nuts. (Although it turns out Pai had already seen quite a bit of evidence to support his story, and she was being a brat.)
 * Averted and Lampshaded when Pai has been locked inside a club with demonic marionettes with her two friends Dee and Ken-Ken stuck outside. When Dee suggests they call the cops, Ken-Ken mentions this trope by sarcastically saying the cops would give them a drug test if they said things that crazy. Dee then says that they should obviously leave the parts about the dolls out and just say their friend was trapped inside a skeevy club ... which is partially true and something a cop with listen to.

Comic Books

 * In Runaways, the kids call the Avengers hotline to report their parents (who are villains). The operator says they always get calls like that around report-card time, and dismisses it.

Film
"Ray: As I explained before, we think the spirit of a 17th century Moldavian tyrant is alive and well in a painting at the Manhattan Museum of Art. Psychiatrist: Uh-huh, and are there any other paintings in the museum with bad spirits in them? Egon: You're wasting valuable time. He's drawing strength from a psychomagnotheric slime flow that's been collecting under the city. Psychiatrist: Yes, tell me about the slime. Winston: It's very potent stuff. We made a toaster dance with it. [gestures to Venkman] And a bathtub tried to eat his friend's baby. Psychiatrist: A bathtub? Venkman: Don't look at me. I think these people are completely nuts."
 * In The Mist, David Drayton makes a very lame attempt to tell Norton about "the creatures in the mist". Even his companions comment this to themselves.
 * In The Cabinet of Dr. Caligari, Frances suspects that Caligari and Cesare are responsible for the murder of Allan, a point he argues very poorly to the police, although justified because . This is more pronounced in the remake, which had sound.
 * The final scene of Soylent Green, in which Charlton Heston's character desperately shouts the titular staple's secret ingredient, is often played as this in Shout Outs / Parodies, but actual scene doesn't really fit the trope.
 * In Ghostbusters II, the Ghostbusters are institutionalized when they try to inform everyone that the subways are filling up with malevolent slime and that a painting in the Metropolitan Art Museum is coming to life at Midnight New Year's Eve. In a minor subversion, Peter is Genre Savvy enough to realize that acting crazy and hysterical, as per the trope, isn't going to do anyone any good; unfortunately, the others aren't:


 * This is despite the fact that, in the previous movie, a giant marshmallow monster rampaged through the town. Somehow everyone believes that it was a trick.
 * The original ending of the 1956 Invasion of the Body Snatchers defines this trope, when the main protagonist (Kevin McCarthy) runs down the highway hysterically screaming at passing motorists that "They're here! You're all next!". The aliens even let him go, pointing out that no one's going to believe him anyway (and especially not if he's acting as hysterically as that).
 * However, the studio was not satisfied ending on such a dark note, and added a Framing Device of the hero in a hospital telling his story to a pair of FBI agents, who don't believe him either... until a passing orderly mentions a car accident involving a truck full of strange, vegetable-like pods.

""Goddammit, David, please believe me! You'll kill and make others like me! I'm not having a nice time here.""
 * In the 1978 remake, McCarthy makes a cameo appearance at the beginning, still trying to tell people "They're here!" He's subsequently hit by a car and killed.
 * In Galaxy Quest, Jason Nesmith tries to tell his co-stars that the odd-looking fans at the convention were really aliens: "They were termites...or dalmatians!" They don't believe him at first, even when a couple of the Thermians (shapeshifted into humans) arrive.
 * This is ridiculously common in slasher and monster flicks where the hero(es) have to warn the general public of the impending danger.
 * For example, in Beware! The Blob!, the female lead witnesses the eponymous monster's first two victims, then almost becomes a victim herself. When it comes time to alert the public, the most coherent thing she can utter is "It came after us; it came after us!" She does get a little better by the end of the film; but by this time, as per the dictates of the trope, her credibility is done gone shot.
 * Somewhat reversed in An American Werewolf in London, as it's one of the walking corpses who's trying to convince the living protagonist, who dismisses them as a hallucination.

"Cop: Hey, is this like the time you found the critters that turn into monsters when you feed them after midnight?"
 * Subverted in Star Trek; when he's figured out what's going on, Kirk races into the bridge like a madman yelling about how it's a trap. Given his actions—plus the fact that he's pretty much a stowaway—Captain Pike is within seconds of having him locked up when Uhura validates Kirk's story with evidence and Spock (who has been given no reason to like Kirk) acknowledges that Kirk's theory is logical. This plus the fact that Pike wrote his dissertation on the anomalous event Kirk is trying to prove is happening a second time, and Pike gives Kirk the benefit of the doubt.
 * In the recent kids flick Aliens in the Attic the kids dial 911 to report the eponymous aliens. The policeman at the local police station dismisses this as a prank call and later turns up at the house to lecture them about it.
 * A review of Evan Almighty posed the question that never seems to be answered in those kinds of movies—so Steve Carell tells his wife he's been chosen by God to recreate the Noah story and that's why all this weird stuff is happening. She doesn't believe him. Why doesn't he take her into the bathroom and show her how his beard grows back immediately when he shaves it, and so on? (Of course, the movie as it is depends on characters assuming that everything that happens to Evan is some kind of misguided attempt at humor he's engineered and is now refusing to let go, no matter how miserable it clearly makes him and how much he insists that it's not his fault.)
 * Given the idea behind Evan Almighty, in that case it's probably done as a point about the Christian concept of faith, which is to be expected of believers without the demand of proof.
 * The eponymous character in Coraline attempts to contact the police and explain that her parents were kidnapped, but once she gets to the part about the Other Mother, they shrug it off. Admittedly, she could have at least convinced them that her parents really were missing, but that doesn't mean they could do anything constructive. She also tells Wybie what's going on, but she doesn't try very hard to convince him, and is more venting at him than trying to explain anything. (Also somewhat justified by Wybie being rather a smart-arse.)
 * The Goonies had Chunk get away from the Fratelli's and find a phone. Unfortunately, he's cried wolf before.


 * Speaking of Gremlins, this is what happens when the hero tries to explain the title creatures to the cops. And again in the sequel.
 * Kyle Reese and Sarah Connor's rantings about a future war and sentient computers in the Terminator films gets them both labeled as nutters. By the second film, Sarah has even been institutionalized.
 * Played with in Small Soldiers. The main heroine is trying to call the police to help them against the attacking toys, and insists that it's not a prank call. Then she reverses herself and says that it is, "So you'll come over and arrest me, right?" They hang up.
 * Generally averted in The Midnight Meat Train, where the protagonist (played by Bradley Cooper) is quite reasonable and diplomatic with the police detective, accepting that the evidence he has is not enough to convict Vinnie Jones of being a Serial Killer. Unfortunately,.
 * The Whole Nine Yards: Sophie says this to the police when she's being interrogated about hiring a hit man to kill her husband.
 * Basically the entire plot of A Cry in the Wilderness, in which a father, suspecting that he might have contracted rabies, chains himself up in a barn, telling his son not to release him under any circumstances. Later he realizes that there is an imminent flood.
 * The Lady Killers uses this as a Framing Device, with a little old lady telling the desk sergeant at her local police station about how a gang of criminals used her house as the base for a bank heist. The story, of course, is true, and the sergeant, of course, doesn't believe a word of it.
 * In the first few minutes of the 1982 version of The Thing, some Norwegians land their helicopter near the American base and start shooting at (what looks like) a Siberian Husky. When some of the Americans come out to see what all the fuss is about (including the security guy with his revolver), instead of dropping their guns and de-escalating things, the Norwegians keep excitedly shouting (in their native tongue) and shooting at the dog. The security guy pops them both before they can tell the Americans about the dog-thing.
 * Which is a bit of contrived stupidity in that using lethal force to prevent cruelty to animals is not a proportionate use of force. (It's understandable, but it still leaves you explaining things to a jury.)
 * In American Dreamer, Alan tries to explain things to the police, but he gives poor context for the situation, making the woman who thinks she's an adventure novel heroine look credible.

Literature

 * In the sixth Harry Potter book, Harry is suspicious about Draco but unable to keep his calm about the matter, and even his best friends suspect that he's not being entirely sane about the whole thing.
 * Harry is terrible at this in general, and never learns. One could blame the other characters for the same thing as Harry is almost always at least slightly right about whatever crazy conspiracy he's crowing about, but he's always screaming and shouting at people when they show even an ounce of reasonable doubt, rather than, you know, presenting any actual evidence...
 * Aside from Dumbledore and Sirius, everyone always seems to disregard Harry's theories almost offhand. In the first book, nobody wanted to hear that he thought the Philosopher's Stone was being stolen, in the third, nobody listened when he claimed Sirius was innocent and Peter Pettigrew was still alive, he spends most of the fifth trying to convince the world Voldemort was back, and in the sixth nobody, including his personal friends, believe him when he says Malfoy is a Death-Eater. This does have an instance of Crying Wolf and people do take him seriously at times (like when Mr. Weasley is attacked), but by the end of the Sixth book, when Professor McGonagall is point-blank asking him for his input on something, he keeps it a secret, having apparently decided Adults Are Useless.
 * Harry's problems with communications can at least be blamed on a truly shitty upbringing under the Dursleys where he has trouble making friends and most of his social interactions with people were doing chores for his aunt and uncle. And he does have rather a good reason to not bother with McGonagall, as she'd previously flat-out refused to believe him about the Stone, Malfoy, and Umbridge. Note: The business about him making friends? Well it was because up until he went to Hogwarts..his cousin Dudley went to the same school as him..and according to the first book "At school, Harry had no one. Everybody knew that Dudley's gang hated that odd Harry Potter in his baggy old clothes and broken glasses, and nobody liked to disagree with Dudley's gang."-Chapter 2 Vanishing Glass last line of the chapter. and "He had always been last to be chosen (in gym), not because he was no good, but because no one wanted Dudley to think they liked him."-the Sorting Hat Chapter.
 * It is instructive to note that it isn't until book 6 that Harry actually makes a friend by his own efforts. Every friend Harry had previously made in the series had approached him with the intent to befriend, because Harry didn't know how to talk to anyone.

""He met a waggoner and tried to make him understand, but the tale he told and his appearance were so wild--his hat had fallen off in the pit--that the man simply drove on.""
 * In the book of Freaky Friday, the protagonist starts, well, freaking out for a variety of reasons, one of which being that while she is inhabiting her mother's body, her mother has presumably gone joyriding in hers, and is now nowhere to be found. She decides to call the police. Instead of saying, "I'm deeply concerned that my daughter has vanished", she decides to blurt out the whole body-swapping story. The cops, unsurprisingly, think she's nuts.
 * In A Song of Ice and Fire, Arya overhears a pair of people discussing their massive gambit. However, with most of the discussion going completely over her head, what she does remember of it when she tells her father sounds completely nuts, even though her father is currently investigating part of said gambit. Except it's not, actually, she just thought it was and presented it to him as such, so he was perhaps right to ignore her (the discussed gambit hasn't actually impacted the plot... yet), if for the wrong reasons.
 * Near the end of The Sharing Knife: Horizon,
 * Averted in the Darkest Powers series by the main character, Chloe. In the first book, she's sent to a group home, where she's diagnosed (incorrectly) as a schizophrenic—she's actually a necromancer. After realizing that she and the other kids are in danger, and then escaping and being chased down by the staff with tranquilizer guns, Chloe manages to get to her Aunt Lauren's house. Once there, she immediately tells Lauren about being hunted down by the staff. But rather than blurt out the entire insane story to Lauren, Chloe leaves out the part where she's a necromancer, ghosts are real, she accidentally raised the dead, and the people she was fleeing with include a fire half-demon, a sorcerer, and a werewolf. And, in an even further aversion, before going to her aunt, Chloe actually takes the time to go back to the scene to bring evidence in the form of a tranquilizer dart, because she knows that she'll be just brushed off as crazy otherwise.
 * Happens often in Goosebumps books—in fact, one of the short stories in the collection More Tales to Give You Goosebumps is actually titled "You Gotta Believe Me!".
 * In H. G. Wells's The War of the Worlds the standard for appearing mad was much lower than in more recent works. Having a bare head would do it:

Live Action TV
"Buffy-in-Faith: Giles, you turned into a demon and I knew it was you! I mean, can't you just look in my eyes and be all intuitive? Giles: (suddenly interested) How did I turn into a demon? Buffy-in-Faith: Oh! 'cause, uh... Ethan Rayne! And-and you have a girlfriend named Olivia, and you haven't had a job since we blew up the school... (beat) ... which is valid, lifestyle-wise. (Giles is abashed) I mean, it's not like you're a slacker type or - Oh, oh! When I had psychic power, I heard my mom think that you were like a stevedore during sex. Wh- Do you want me to continue? Giles: Actually, I beg you to stop. Buffy-in-Faith: What's a stevedore?"
 * Sort-of subverted in the Buffy the Vampire Slayer episode "Bad Girls" from the third season. After Faith, Buffy agonizes over what to do for deciding to tell Giles...only to find Faith has beaten her to it and blames it on Buffy. When Faith is gone, she pleads with Giles to believe the truth...and finds he does quite unequivocally, Faith having "many talents" but lying not being one of them. He also notes almost casually that , and that it's dealt with internally by the Watcher's Council.
 * Which leads to a rather sad and long case of Poor Communication Kills with Faith as she becomes so closed off about it and paranoid that when she hears the rest of the gang talk about how they're going to "deal with her" she assumes the worst while in truth they are probably considering hiring a therapist and contacting the Council to do a clean up job.
 * Sort-of subverted again the fourth-season "Who Are You?" when Faith switches bodies with Buffy. Buffy is quite able to convince Giles that it's her by rattling off a string of rather embarrassing facts about their relationship that Faith couldn't know.

"Buffy: I can't believe you of all people are trying to Scully me!"
 * Played straight, if fairly subtly, in both Buffy the Vampire Slayer and Angel: If Angel wants someone to invite him into their home so he can protect them, he won't say "May I come in?"; he will instead demand that they invite him in. This makes him sound like a crazy person. They never do.
 * Another Buffy example: In the episode The Pack, Giles refuses to believe Buffy when she claims . Being Buffy, she calls him on it:

""I don't see why anyone would find anything odd about our appearance.""
 * In The Outer Limits episode "The Special One", a father asks the board of education if they provide tutors as part of the enrichment program. When he's told that they don't, he reveals that a man posing as a tutor has been visiting his son. And then he reveals that the man isn't human, is from outer space (which he couldn't possibly know), disappears and materializes, and then starts talking about climate control machines.
 * Mulder of The X-Files has a bad habit of this; when trying to enlist outside aid in dealing with a case (local police, FBI higher-ups, etc.) he makes sure to tell them exactly what he thinks is going on, no matter how insane, as opposed to sticking to the parts they're likely to believe.
 * This becomes almost something of a Running Gag, since no matter how crazy the theory and how much Scully cites scientific research that he's wrong, Mulder is always right.
 * As well, some of The Men in Black are pretty Genre Savvy about this, deliberately acting as strangely as possible and using agents who look like famous people (or perhaps even making an agent, say, the host of a game show), so that anyone who tries to tell other people about them won't be believed.

"House: IT'S NOT LUPUS!"
 * In the episode Synchrony, an elderly man (who's actually from the future) approaches two guys and starts a rant about how one of them will die in a traffic accident while crossing the street that evening, and how this must not happen. Of course, they don't believe him. If he'd calmly started a conversation with them and held them up for just a few minutes, he'd have easily succeeded.
 * Played with in the first episode of the 2005 series of Doctor Who, when Rose meets with a conspiracy theorist who has information about the Doctor (whom she has kept mysteriously bumping into). Initially, he starts off presenting his theories about why the Doctor keeps popping up in different parts of history in a calm and reasonable fashion, and presents a relatively plausible theory that she'd be likely to believe—they're all different men who are related and sharing a codename. Then, as he gets a bit carried away with having an audience, he starts getting a bit more worked up and intense, until he's convinced that Rose believes him fully and so blurts out his real theory (which is the truth) -- that they're same man, and the Doctor is an alien traveling through time. Unfortunately for him, he hadn't quite won Rose over before this, who leaves believing that he's a nutcase.
 * The Doctor, as often as not, explains that a giant psychic carnivorous alien plant is about to destroy the planet, even if everyone would be much better of if he'd come up with a plausible lie, deal with the alien, and explain later. This usually results in him being called a nutter and locked up, even if the people he's talking to should have every reason to find giant psychic carnivorous alien plants perfectly plausible.
 * One of the Big Finish Doctor Who audio plays, Minuet in Hell, has the Eighth Doctor lose some of his memory after crashing the TARDIS and winds up in a mental hospital. He tries to tell people his name and what happened, and tells the Brigadier when he shows up that he (the Doctor) recognizes him, but no one believes him, because, well, he's in a mental hospital (the Brig doesn't recognize him because he hadn't seen that incarnation before).
 * Averted in "The Eleventh Hour": The Doctor breaks into a house, and keeps shouting about Prisoner Zero. He is knocked out cold, cut to a hospital. Despite our expectations, he isn't there.
 * Later played straight in the same episode when the Doctor does beg Amy to "believe for twenty minutes."
 * The Doctor's pleas to the alliance at the end of The Pandorica Opens.
 * This is Tru's default state in Tru Calling. When subtler methods of informing people of their own impending death fail or are sabotaged, she always falls back on this line. Not only does it never help, it was likely similar antics from Tru's mother (who had Tru's powers) that got Davis' wife killed, so Tru should really know better.
 * Subverted in an episode of Stargate SG-1, where after relating a prophetic dream he's had to General Hammond, Dr. Jackson is surprised when Hammond asks what he can do to help. When asked why he believes Jackson, Hammond gets Genre Savvy, alluding to all of the other crazy things he's seen and heard while in command of the SGC.
 * Also played straight in several episodes. In the three episode arc that ends the first season  Later, and more (though not entirely) excusably,   The latter is also a massive case of Hollywood Psych.
 * The same thing later happened to Jonas Quinn. When he starts seeing bugs that no one else can see, Hammond immediately orders a lockdown and a full sweep of the base. Granted, Jonas was the only one to touch the strange alien device, but he was also the only one who'd spent his entire life around a specific type of radiation that's known to cause schizophrenia, so, well...
 * Doctor House from House MD is a brilliant medical expert who nails the most bizarre diseases and syndromes week after week, yet nobody ever believes him when he dismisses the obvious diagnostics of the other doctors, despite there always being a nagging little detail that derails the simple explanations. Oh, and the standard treatment to the obvious diagnostic always seems to instantly kill the patient if administered before House stops them.

"House: I'm almost always eventually right."
 * Then again, it doesn't help his case that he's a sarcastic curmudgeon with a bad case of pain killer addiction...
 * Plus House himself will usually come up with a completely wrong diagnosis, that nearly kills the patient, before he comes up with the right one.

"Gibbs: Skipper, I have reason to believe a bomb, possibly containing a biological agent, is set to detonate aboard this ship by sunset. Captain: How real do you think that threat is? Gibbs: (flatly) Very real. Captain: (immediately turns around to face the XO) Sound General Quarters. Deploy the flying squad, start with the ventilation systems, and alert sickbay to the situation and have them stand by."
 * An episode of Season 2 of Amazing Stories is actually titled "You Gotta Believe Me". It involves a man who has a horrific dream of a plane crashing into his house in the middle of the night. As he walks among the wreckage, he sees ghosts of some of the passengers and the ghost of the pilot talking about having to attempt take off too early due to something being on the runway. He wakes up and, while still in pajamas and robe, heads to the airport. While there, he sees the things that were part of the wreckage in his dream (including a girl's Teddy Ruxpin toy) and some of the ghosts. Convinced his dream was a prophecy, he keeps trying to convince the passengers, crew, security and so on that the plane's going to crash and gets more and more frustrated by people not taking him seriously. In the climax, he's on the tarmac and sees a single-engine plane with a drunk pilot taxiing onto the runway, heading into the path of the airliner. He rams the plane with a forklift, saving the passengers. Security grabs him and he says: "They were going to crash! You gotta believe me!" At which point, they finally do.
 * Happens so, so, so many times in The Time Tunnel. The two protagonists always jump straight to "We're from the future," never bothering to come up with some more plausible explanation for how they know what they do, no matter how many times it doesn't work. Though it is nicely subverted in one episode where Doug confesses everything while being affected by a truth serum, which just causes his captors to think he's been conditioned to resist the serum and consider this proof that he's a professional spy.
 * Oddly enough, it happened constantly on Star Trek. Someone would claim to see some kind of anomaly in their quarters, have been abducted, been contacted telepathically, or whatever. Yet, the crew would always look at the person as if they were insane, even though that kind of stuff happened every single week.
 * Star Trek: The Next Generation, on the other hand, played this straight to start with, then tended to avert it once the beard filled in and the main characters learned to trust each other, generally responding to outlandish claims with a sensor sweep or system diagnostic - which, naturally, rarely turns up anything at first - before suggesting a sleeping pill and a nice lie down. (It still does go straight occasionally, but there's always a valid reason given for why.)
 * A good example of this is "Realm of Fear", in which minor character Barclay, who has a well-deserved reputation as a twitchy, paranoid hypochondriac, spontaneously develops a fear of the transporters, insisting that he's been bitten by something living inside the beam. Picard gives him a long, hard look... then tells Data and Geordi to tear the transporter apart looking for the problem, because he knows that Barclay is fully aware of his reputation, and wouldn't risk the humiliation of reporting to him directly unless he were absolutely positive.
 * The final episode plays with every aspect of the trope, with Picard traveling through 3 time periods. The present crew believe him outright. The future crew has doubts, since future!Picard is suffering from a brain disorder known to cause delusions, but he calls in some favors and they go along out of a sort of familial duty. And in the past, having "just" arrived on the Enterprise, he simply opts to not tell them at all and just starts barking out orders.
 * Commonly averted on NCIS.
 * Witness this exchange from "The Immortals":

"Graeme: (in close-up) Anyway, I sent that rabbit up to the moon...uh, that was Flopsy. But he didn't come back, so I sent Tim and Bill up to the moon to see what had happened, and when they got up there, they found all these...carrots. And then hundreds of rabbits attacked them and overpowered them...(zoom out to reveal two uniformed men are grabbing him) ...and they've just gone into the space-burrow and they've met Big Bunny. (gets fastened with sign reading 'LOONY -- handle with care') No, honestly, it's the truth, it is the truth, and Big Bunny's teaching them to say 'Nyeeeeh, what's up doc'! (gets stuffed into a crate reading 'TO THE FUNNY FARM -- this side up')"
 * Another notable example is "Enigma", in which Gibbs' old CO enters stage left exemplifying this trope in full, with breathless panicked warnings about a massive black ops conspiracy going to the highest levels of the US government that's illegally manipulating wars, siphoning money out of Iraq, faked the death of Gibbs' old platoon leader to use him as one of their black operatives (before he defected to the colonel's side), and going to kill him.
 * The Daily Show: Played for Laughs by Rob Riggle's character, whose often somewhat valid points which are completely overshadowed by his borderline psychotic personality.
 * Played with in Quatermass 2. The title character is trying to get a committee of Obstructive Bureaucrats to authorise an inspection of a well-guarded synthetic food factory, which has some connection with strange hollow meteorites landing in the area. A politician who also wants to get to the bottom of the matter agrees to help him, and starts pitching to the committee the idea that the factory might be in danger from these meteorites crashing down on top of it. Rather than realising what he's up to, Quatermass keeps interrupting to 'correct' the politician's supposed scientific error.
 * Burn Notice: "Burn [Notice] After Reading" has a guy going to Michael claiming that a woman at his workplace is an alien bent on world conquest. While the client is obviously delusional,
 * This is also happens to their opponent one week. When Michael finds out about a well connected father who was beating up his wife and kids, he decides to do something about it. The problem is that his brother is a gangster and therefore they have to drive a wedge between them.
 * Get Smart: Events in "The Little Black Book" force Maxwell to tell an old friend of his that he is actually a spy instead of being in the greeting card business. He isn't convinced until Max drags him to CONTROL headquarters (by way of the telephone booth) and has him talk to the president on the cow horn phone.
 * Firefly: The parents of Simon and River Tam have some excuse for not believing their son when he claims their daughter, supposedly safe at a government school, is being tortured and tries to hire criminals to kidnap her. As it happens, Simon is absolutely right, but it isn't exactly the most believable of stories. A deleted scene implies that they didn't completely disbelieve him either, but were also afraid to go poking around in Alliance business.
 * Misfits: Nathan yells dramatically at his mother that her boyfriend is a "psycho, rough-trade, gay, rapist werewolf!" Granted, his mother probably wouldn't have believed him even if he'd just calmly explained the situation (especially considering that Nathan is pretty much a compulsive liar, and had leapt to a rather silly conclusion based on what he'd seen anyway) but by the time he realised that babbling like a crazy person probably wasn’t doing him any favours, she'd already totally dismissed him.
 * This is the title character's usual tactic in Merlin. He never has any proof, because obviously A Wizard Did It, and so it never works. You'd think he'd learn after a few tries. Or alternatively, you'd think the other characters would learn that no matter how insane Merlin's initial claims may seem (or however badly he goes about explaining it), he's always -- always—proven to be right by the end of the episode.
 * Intentionally invoked by Frank in Seven Days. When a journalist is about to expose the governments time-travel experiments he confirms her story on national television. He then goes on to say that he is the only man that can time travel, which is why the CIA let him out of the psych ward so he can pilot the ship that runs off of alien technology found at Roswell and designed by a sexy Russian that totally digs him. He (and the journalist) are laughed off the show.
 * Interesting case on Wire in The Blood: after the police crack the M.O. of a serial killer, it becomes vitally important to alert his latest prospective victim (who is already waiting to meet him) to the danger, without spooking her into hanging up or dismissing the call as a prank. Psychologist Tony Hill immediately demands that he be given the phone; he then adopts exactly the right inflection so that she not only listens to him, but believes him, gives the police her location, and agrees to lock herself into a bathroom stall until he will arrive, using his name as a pass word. This is an inversion in that it is the police convincing a citizen of a sinister plot and not vice versa, and an aversion in how professionally the task is handled. However, while Hill is a brilliant theoretical analyser of criminals, he is also shown as very socially inept and in fact often more of a liability when interviewing friends and relatives of victims. For him to be that convincing is actually out of character, which might count as a hyper-aversion.
 * Played for laughs in an episode of The Goodies called Invasion Of The Moon Creatures—the audience has followed everything that happened and knows that it's true, but of course, it sounds insane summing it up. Context: Tim and Bill have been brainwashed by moon rabbits, and Graeme pleads for help with the authorities.

"Dean of Air Conditioning Repair: We don't want you to tell anyone about this, and if you do, we don't want them to believe you, isn't that right black Hitler?"
 * Community:
 * Phrase is spoken by Britta when she is trying to unsuccessfully convince Tory and Abed that their friend Lukka is actually a war genocidal war criminal.
 * Invoked by the Greendale Air Conditioning Repair Initiation. It's supposed to be secret, and so they kidnap people in the middle of the night, there's an astronaut in the corner making paninis, to ensure that any story would sound insane.

Videogames

 * Arcanum's (in)famous X-Files quest ends this (as well as It Was Here, I Swear) way: when you try to expose the conspiracy, you realize your proof was just, let's say, stolen. For added trauma, when you return to the secret facility where you found it, there's nothing, not even a brick. There are even a number of relatively obscure minor characters (along with a major one) to whom you can present your evidence, but they all either end up dead, have the files stolen from them, or are actually working for the conspiracy.
 * StarCraft
 * In StarCraft: Brood War, Aldaris incites a major military revolt and goes off on a mindless tirade about how evil the Dark Templar are and how they would doom the Protoss society. Just as he is finally defeated and starts to explain what he's discovered, Kerrigan pops in and assassinates him. The heroes eventually find out the hard way that Aldaris was right two campaigns later....all because the guy descended into a raving lunacy rather than rationally approaching the dilemma.
 * Almost completely subverted by Zeratul in Star Craft 2. True enough, he starts out as if he's going to play this trope straight, coming to Raynor in a dark corridor and acting all crazy and hurried, but he does give ol' Jimmy all of the information he has, expressed as logically as possible. It's also hard to fault him for boarding the ship in secret, because, well, he's a Protoss, and that's just the way they do things.
 * In Warcraft 3, the Prophet  could have done a much better job of warning the human leaders of their impending doom, if only he didn't barge into the throne chamber uninvited in the shape of a raven, transform into a human before the King, insult him, and then proceed to ramble about doomsday like a lunatic.
 * Considering that the magi of Dalaran and the elves of Quel'thalas were very much aware of the existence of demons, all the Prophet really had to do was bring up the topic and say, "yeah, they're coming."
 * Subverted in Persona 4. After trying out the local rumor (looking at a blank TV screen on a rainy night will reveal your soulmate), the protagonist, Yosuke, and Chie are all talking to each other about their experience the previous night. The main character, unlike the other two, was a bit more hands-on, and managed to fit his head into his TV, which he then calmly and casually explains to them. Thinking it to be dream or a bad joke, Yosuke and Chie take him to the electronics aisle of the local department store, sarcastically suggesting that he could climb right in through one of the flatscreen televisions. When they suggest for him to prove what he said that he did, he promptly sticks his hand into the TV, and then, when curiosity overtakes him, his whole upper torso, at which point Chie and Yosuke begin freaking out.
 * Unfortunately played straight if he tries to tell his uncle about it later. Despite the TV in the room.
 * In Mass Effect,
 * Later games reveal that even dragging a dead Reaper in front of the Council or getting testimony from a Prothean VI or, indeed, anything short of the actual full-on Reaper invasion itself, will not be enough to convince the Council. At this point one wonders if its fair to blame Shepard at all.
 * In the final scene of Wing Commander IV: The Price of Freedom, Blair, having witnessed evidence of, interrupts a Senate hearing to try and present his case. The player is presented with dialogue options that determine how he goes about this, but the straighter you play this trope, the less likely the Senate is to actually believe him, to the point of bad ending yourself.
 * In The 1st Degree: James Tobin goes into this a few times. What really makes him look bad is how early on, he changes most of his story, saying that he was so scared and that he did not think anyone would believe him. He even admits to shooting himself in the leg because he wanted to make the situation he was in look like like it was self-defense.
 * Averted/Defied in Gothic II. When the Nameless Hero has to gain Paladins' support against the dragons in Valley of Mines, he simply tells their commander, "The question is not if you should believe me, but whether you can afford to not believe me if I'm telling truth." It works pretty well—the Hero is sent to the Valley for confirmation.
 * In Skyrim, the Thanes are faced with some pretty outlandish stories from their population and might easily fall for this trope, although they have the good sense to ask you to go look into that mysterious cavern just to be certain. Surely enough, no matter how crazy the story was it all turns out to be true.

Web Comics
"Mary: I'm sure I could have handled that better."
 * Lampshaded in Casey and Andy when Mary calls 911 to say that Satan was kidnapped by a mime assassin and gets hung up on.


 * Used as a Running Gag in Sequential Art, whenever Art calls the police to resolve the current bizarre crisis. Naturally, they always hang up. The next trouble happens, and he does it again.
 * Averted and Lampshaded in Girl Genius when Agatha tries to convince Von Mekkhan that she is the Hetrodyne heir. Von Mekkhan has seen stranger things than talking cats, and while he has seen a lot of pretenders come by, he is willing to give Agatha the opportunity to make her case.
 * The Unspeakable Vault of Doom follows the Mythos in this. Case in point: Migos let a guy go...

Western Animation
"Homer: Why won't anyone believe my crazy story?"
 * Monster House: An abandoned house eats anyone who approaches it. The kids tell the police this (loudly), instead of "someone went in and never came out".
 * The movie Chicken Little uses this one a lot. Chicken Little's flabbergasted babbling as he attempts to explain himself isn't exactly helped by his own father apologizing for his craziness to the townspeople.
 * Appears in Mulan, as she struggles to tell her former teammates that some of the Huns have survived an avalanche that buried their army.
 * The Simpsons
 * In the commentary for "Homer's Enemy" (featuring the line "This whole plant is insane! Insane, I tell you!") the writers note that if you're trying to convince people you're not crazy, it's not a good idea to end any sentences with "I tell you." Or worse, "I tells you."
 * Lampshaded in one "Treehouse of Horror" story where Kang and Kodos abduct Homer and spray him with booze before releasing him so that his warnings will be dismissed as drunken ravings.

"Orin: He's only telling you what he wants you to believe! Zygon: (entering the chamber behind Orin) Because I want you to believe the truth!"
 * Subverted in Starchaser: The Legend of Orin, when Orin is trying to convince the others of the existence of the outside world and gets interrupted by Zygon.

""He's a chicken, I tell you! A giant chicken!""
 * One regular feature on Animaniacs was Chicken Boo, about a giant chicken (rooster?) who puts on human clothes and tries to blend in. Everyone is always completely fooled until his glasses/hat/what-have-you falls off, save for one loony guy raving throughout the short:

"Gambler: There's a gremlin destroying the plane! You've gotta believe me! Narrator: Why should I believe you?"
 * Futurama
 * Used humorously in the Show Within a Show, The Scary Door:

""Mom! Mom! Come quick! Phineas and Ferb are (insert this week's completely impossible-sounding scheme here)! You have to see this!""
 * Professor Farnsworth's effort to explain the dark secret of Slurm is ruined when he identifies Fry as his uncle from the twentieth century. Which is possible, but presumably rare enough that when Fry denies it they assume he's just crazy.
 * Plus, he's the professor. Pretty much anything he says has a fifty-fifty chance to be dismissed on its own merit, and rightfully so.
 * In "In-a-Gadda-a-Leela," the crew discover that Earth is going to be destroyed by a giant automated death-sphere-ship thingamabobber, because it's "censoring" inappropriate planets by destroying them. Farnsworth states that people will listen to rational, intelligent people such as them. They emerge seconds later in robes and signs, saying "The end is near!" and "Repent!"
 * In an episode of DuckTales (1987), Ma Beagle's latest scheme involves pretending to be married to Scrooge McDuck. Scrooge's attempts to deny being her husband fall under this trope, especially when she demands a "divorce" (meaning that she would get half his fortune), and he blurts out that he'd rather "stay married," which of course the judge interprets as meaning they already *are* married...
 * In Recess: School's Out, three different groups of people report strange happenings in Third Street School: TJ reports the green laser, his friends report his kidnapping, and even the typically unhelpful Ms. Finster reports ninjas. And yet, the cops make no connection and just laugh each one out of the room.
 * Duke and company in G.I. Joe: Renegades. The kind, benevolent, paragon of corporate responsibility that is Cobra Industries couldn't possibly be evil, could they? Starts to be gradually subverted as word of their heroic exploits gets out, and even Flint sees evidence that something much bigger is going on.
 * Phineas and Ferb: This is the entire raison d'etre of older sister Candace.

""FAIRY GODPARENTS!!!""
 * Likewise, Evil Teacher Mr. Crocker from The Fairly OddParents, although he tends to not be quite so lucid when stating his case.


 * The protagonist in Looney Tunes' One Froggy Evening follows this trope to a T when he utterly fails to convince anyone (talent agent, theatre full of patrons, a policeman) that he is in possession of a singing frog.
 * Invader Zim: This is the entire reason why nobody ever listens to Dib, not even his sister who knows that he's correct about Zim being an alien invader.