The key here is that they are mistaken for firecrackers FROM A DISTANCE. It’s totally different when you hear one close-up, particularly a large-caliber handgun such as a 45 or a 357 Magnum. Have someone fire a 357 Magnum within a few feet of you with no hearing protection sometime and trust me, you won’t mistake it for a firecracker.
Another un-truism is that the biggest, burliest men can always pull off convincing drag. Convincing enough that at least one bad guy will fall for him before they get out of there.
[ul][li]In any city, at any time of day or year, the protagonist will be able to find a parking space immediately in front of the building he/she is going to.[/li]
[li]Everything in the movies explodes with the yellow fireball characteristic of gasoline fire, even when the flame is supposed to be from some other fuel, i.e. natural gas. IRL, dynamite, high explosives, and military munitions do not usually give off fireballs. [/li]
[li]In major action films (e.g. James Bond) even though the good guy and bad guy have been showing off all sorts of high-tech weapons, the film’s climax will always come down to a fist fight between them.[/li]
[li]Highly elaborate and sophisticated plans, including reworking systems to do things they’ve never done before (this is especially common in science fiction, and particularly Star Trek) in very short time periods and with very high stakes, always work perfectly the first time. IRL, I couldn’t get the supposedly simple installation of a gas stove to go smoothly.[/li][/ul]
You can shoot someone in a car or other small, enclosed space, then immediately continue a conversation… no hearing damage, no ringing of the ears, nothing.
Almost all lifeforms, throughout the universe, have essentially the same metabolism and body chemistry, as nearly any space traveller is able to find edible food on nearly any planet.
Artificial gravity technology is so reliable, it continues working for centuries even when the starship in which it is installed is a powerless, badly-damaged derelict.
There are no brand names in bars. You always just order a “beer” and the bartender or waitress never asks what kind.
Whenever you turn on the radio or television a relevant news update will start precisely at that moment.
You can win women over by persistently stalking them, sending them gifts and harassing them at work. Saying stuff like “I won’t take no for an answer” is seen as endearing and attractive.
All important female characters will be good looking. There can never be an ugly female lead.
Addendum: people in horror movies can trip and fall, but only if they’re being chased by soemthing about to kill them.
You can protect yourself from serial killers by not keeping a cat in your house. Police studies show that serial killers always wait for their victims to be startled by the cat before suddenly appearing out of nowhere for the kill.
The funny thing is, the only time I really did run for my life, I did trip and fall. And, strangely enough, this is what saved me.
Other computer-related ones:
-Computer viruses can infect any system.
-Computer viruses must be manually triggered by typing something like “bug” at the prompt.
-If you infect a computer with a virus by inserting an infected floppy disk, you can resume normal operation by removing the floppy from the drive.
-Any man who tries to cook a meal will get flour all over the place. Even if there is no flour in the recipe.
Ehh, I’ll give 'em that, since all movies “enhance” sound to some degree, and it’d be really boring otherwise.
Oh, I forgot: (I get no credit, though, I got that from a chain e-mail)
In the year 3020, humans will have lost the ability to aim weapons at targets outside of visual range.
I just thought of another one.
For the kids out there:
Remember, divorce is only a temporary thing. Your parents still love each other and they can always be brought back together through some amusing artifice or trick on your part.
It’s not like they broke up for any serious reason anyway. There is never any adultery or drug use or anything in family films. The problem is invariably that dad was so obsessed with being a cop/coaching a team/his wacky inventions/his Noble Cause that he forgot to pay attention to his family. He will learn what’s really important after he catches the bad guy/wins the big game/stumbles on his big invention/achieves his Noble Cause but finds that he still feels incomplete without his family. It will be especially helpful if you get hit by a car or something, forcing him to rush to the hospital, reevaluate his priorities and have a tearful heart-to-heart with your mom.
Also, your mom will never boink other men during the divorce, she will just wait for your dad to come back.
All English people are villains/baddies.
Al Baddies smoke.
When driving your car agressively down a dusty dirt road, loud tyre screeching noises can be heard when cornering fast, and braking to a stop.
There’s never a delay between lightning and thunder.
People take dirt backroads rather than the interstate when travelling cross country.
People never use area codes (even though that would allow them to dispense with the ridiculous “555” prefix).
The box lids of birthday/Christmans presents are wrapped separately.
All sorts of havoc can take place in the middle of a downtown without the police ever showing up.
At night, the streets are always wet.
Beat me to it.
Or the second sabre fight in The Duellists.
…Or the final swordfight in Robin and Marion
Well, I try to take back roads whenever possible when travelling cross country. It’s more interesting, you see some cool shit and I HATE driving on the interstate.
A chair, any chair, when leaned against a door, will make the door impenetrable.
We can thank William Hobbs . For most of these exceptions. 
In the movies some dueling swords apparently have a high flint content, because they make sparks when they strike each other.
Do the British infantry squares formed in the movie Waterloo count as part of this exception? When Ney’s cavalry is charging someone rather loudly yells “Aim for the HORSES!!”
(meanwhile the gunners are beating cheeks to the squares)
In fairness to movies, simulating a wounded/dying horse is not an easy task by any means, without the ASPCA getting involved.