The relaxed position of mammalian eyelids leaves them open. Muscles must contract for the eyes to be shut. Dead creatures cannot contract their muscles so their eyes remain open after they die.

You cannot shut their eyes for them by closing their eyes with your hand. Morticians place contacts in cadaver's eyes while preparing the body for a wake. Those contacts grip the inside of the eyelids so that they remain closed.

This is why some cultures have funerary traditions in which objects are placed over the eyes.

TL;DR: you and your loved ones won't close their eyes when they die.

Loudness of gunshots. Every action hero would be deaf.

Archers being told to "hold". Nobody's holding a +100lbs warbow.

Sprinklers. In the vast majority of cases they react to heat - not smoke. They only go off individually rather than all at once and the water inside the pipes is black ink-like rust water sludge, not clear tap water.

Also another plumbing related: you don't need a huge wrench under the sink and drains are not pressurized so there's no water spraying anywhere when you mess with the p-trap.

Sex and relationships in action movies.

The whole "hot chick gets horny for the hero after a traumatizing couple of hours" thing gives a pretty messed up view of relationship building.

Cops being the good guys.

Hacking.
tap tap tap I'm in.
Honourable mention is NCIS Dual keyboard
https://www.youtube.com/watch?v=u8qgehH3kEQ

Telephone etiquette. They just start yapping and then hang up without saying goodbye.

Most dishonest about? Hard to say, since movies are dishonest about virtually everything. (As escapism, that's what we want.) But a big one that comes to mind is proceedings in courts of law.

In real life, a court case is excruciatingly procedural, spread out over months of correspondence and brief hearings, and the vast majority of them never go to trial. And for the few that do go to trial, there are never any intense, witness-stand confrontations, or inspiring speechifying by the plaintiff or defendant. No attorneys shouting, "OBJECTION!", across the room.

I know of two friends of a friend, one of whom signed a reverse mortgage on his house with some scammers who promised that he could live the rest of his life there, but then who turned around and filed to evict him. Clearly influenced by dramatic courtroom scenes in TV and movies, he seemed to think that "court" meant that he would be able to show up and give the judge a moving soliloquy about being a righteous, disabled veteran, and prevail. The judge did his level best to help the guy out by almost insisting on appointing a guardian ad litem (free attorney!), but he refused. (Sadly, he died before it went to trial, and the scammers kept the house.)

The other one got sued by a credit card company over a charge that was obviously bogus (i.e. from a swimming pool contractor in eastern Europe, which is just who you'd call in the midwestern U.S.), but they had the same mental script: Show up in the courtroom and speechify to the judge. They didn't even respond to the summons and complaint, and the company won by default judgement.

It's maddening.

How big a house an average person can afford.

Distances in space.

Everything is further away that you can possibly imagine.

Movies and shows about legal disputes rarely show how long and dragged out they usually are

Hacking.

the classic : no cleanup after sex

Explosion and gun sounds in spaaaaceeee!

Running over a cliff and only start to fall once realizing that you just ran over a cliff.

That's not real, you fall immediately.

Pulling people out of a burning building. In reality the smoke and fire is so bad, you ain’t seeing shit, not like the clear visibility like they show in the movies. And I spoke to a firefighter who’d been doing it for 35 years. The guy was teaching fire safety at my workplace. He said he responded to thousands of burning buildings and the number of times anyone’s been saved out of a burning building? Exactly zero. That always stuck with me.

Getting knocked out for a length of time after being hit on the head is likely going to cause pretty significant brain injury or death.

CPR is so hilariously bad and completely against what is taught in even first aid classes. This includes hospital based medical dramas. CPR is also always successful in movies, but relatively rarely in real life.

If a man and woman consume alcohol, there's an 80% chance that it's about to transition into a sex scene.

Explosions release a crazy amount of fire. In reality explosions are violently expanding gases with almost no flame seen.

Poverty is rarely ever shown accurately. Malcolm in the MIddle was a good example though.

Forensics and science concepts in general are usually fabricated or badly screwed up for the convenience of the plot. "Zoom and enhance!!"

Nobody has that much time in the morning, or they go to bed at 8PM.

I want to see celebrities walking around sweaty in a hot day. Show us the sweat takes!

Bad cell phone reception is also depicted wrong. But I’m not an expert.

Smashing your phone does not reliably disable it. Odds are the data is completely recoverable, and the device may not have even powered down.

Also ghosts. As far as we know ghosts are not real. Yet there’s an entire genre of movies about ghosts with varying rules.

The amount of trauma the human body can absorb is a bathtub curve based on your morality.

NYC should only ever be depicted with giant piles of trash everywhere.

Romantic relationships. Way too much stalking and abuse of power. Far too many very large age gaps. All that stuff.

Getting hit on the head and staying unconscious for an extended period of time.

No... No that's not how that shit works. If you're hit on the head so hard that you are lying on the ground limp, you're either dead, dying, or have received sever brain damage.

Millennials/gen Z with their phone sound on. I get it’s to fill otherwise blank space in the sound, but we’re not texting with the click-click-click-click.

Suppressed weapons. Shit is still loud, anyone anywhere near it will hear it. Also, when a bullet hits a person or any other surface the impact sound is loud as well.

Hitting people with beer bottles. You take a beer bottle to the head and you're probably done for.

Getting knocked unconscious.

Cars explode after an accident.

Passwords can be guessed.

Up and Down exists in outer space.

How easy it is to twist someones neck to kill them.

A whack to the head just puts people to sleep for a few minutes and then they carry on like normal.

Defibrillators. They don't start a heart that is stopped. They stop arrhytmias and give the body a chance to return to a normal rhythm.

How often emotional vulnerability leads to positive outcomes.

How often real people have to go to the bathroom.

How many physical injuries an action hero can sustain and still pull off demanding stunts.

Giving birth. In movies and TV shows it's always this sudden thing. Like "My water broke! The baby is coming!" then there is some pushing and screaming and bam, baby. In reality, having a baby takes many many hours and often times days, even with induced labor.

How heavy a full cup of coffee feels. The actors always treat it like the cup is empty. Liars!

Gear changes in cars. Any car racing or high speed chase these cars are always accelerating and changing through endless gears despite being on a long straight.

Except Ronin, Ronin does it well since the chase is in the city and they're always slowing to avoid objects turn down alleyways etc so going through the gears over and over actually makes sense!

Memory loss/amnesia. It works as a plot device but how often it shows up in media makes it seem like, well that’s what happens when you get bonked on the head. Amnesia is actually pretty rare.

CPR/shocking: I was so grateful that Dr. Robby called this out on The Pitt, you can’t shock asystole (flatline). Well, you can but it’s good for fuck all. I get why CPR is done poorly, if you do it for real you’re probably gonna break ribs. But they could do it as fast as it’s supposed to go at least. The dramatic pushes 3 seconds apart is also good for fuck all.

History

I think familial relationships are often romanticized in movies. I always see siblings act like they are best friends with each other and in my reality my brother and I are just two people. We like each other but I wouldn’t say he’s my best friend and I don’t think he would say it either.

Injections always annoy me. Shanking people in the neck with ridiculously fat needles. Or how bout Pulp Fiction where they stab her through the sternum? Also going in the arm, but the angle’s totally wrong and they’d basically be stabbing right through the vein lol

Getting knocked out. Its super-bad for you.