I assumed this was video game related so I am gonna talk about that one first:
Inaccurate firearm animations
I have been playing video games for so long I am very aware of how most of the modern/common firearms used in games operate, at least when it comes to basic reloading and chambering rounds in guns.
Because games have taught me this extremely unnecessary information, I really hate when games blatantly screw up gun reload animations. Fortunately games have become a lot better at this, and now it usually comes down to me being notably impressed when a developer takes the effort to properly model the reload. That said, an insane amount of games still screw up how handguns work, when you reload a semi-automatic pistol without having emptied the magazine, the slide on the handgun doesn't magically slide back upon ejecting the magazine. The slide only locks back when the gun is out of bullets, this allows you to reload and chamber the next round without having to pull the slide back manually, which is sometimes pretty hard.
What makes this extra annoying (to me), is that it would be less work to just never have the gun lock it's slide back. Some pistols do not automatically lock the slide back upon using the last round, plus most of the time, players reload their guns before they are entirely out of bullets, and the slide should only lock back if every round in the gun has been expelled.
That said, huge bonus points when games do get the animations right and have two reload animations based on whether or not the gun is dry when being reloaded. And an extra point if the game actually includes the extra round when reloading a gun that hasn't expended all of its shot. One weird example is Payday 2, which has separate reload animations for their weapons, but doesn't reward the extra round. I assume this has to do with balancing, especially since some weapons have very limited magazines to balance out their power (like the heavy sniper, takes 2-3 shots to kill the strongest enemy, adding the extra round would let you kill 3 bulldozers without having to reload).
My real life nit pick is a lot less interesting, I hate cellphones and people who use them while I am trying to talk to them. People who use phones at dinner tables are annoying but what really pisses me off is when people stop to take phone calls during a conversation, the entire point of a cell phone is being able to make calls at any time, it is not imperative that you answer the every phone call when it happens, people can wait. If they are in an emergency, they should call emergency services.
