There's always that person who is constantly judging everyone around them, and it's just rude to be honest. This person is quick to pick out any flaw, any mistake, and it's almost like they get pleasure from putting others down.

This person will usually be found sitting at the back of a classroom just staring everyone down. They think they're so much better than everyone else. Usually they're not. Usually they're just plain annoying.

This person irritates the hell out me.