Why are people so mean to eachother and so angry?

Lots of people are miserable and fucked up and they take it out on others because they don't wanna be miserable alone. People are overall selfish.
The best thing you can honestly do is be happy and kind in return, it pisses them off because they didn't succeed in bringing you down. That is if you can manage to keep your cool and have a good attitude which isn't so easy when someone tries to upset you.

I’m not mean.

Because they dont have to see you face to face. People will talk crazy to everyone and anyone over the computer but if you are infront of them they wont. I find it cowardly I try not to say anything I wouldnt say to someone's face.