A characteristic that I hate is Narcissism. It is a totally revolting quality in a person. A person I know has this quality. His motto in life is 'copy from others and then call them copiers'. Whenever he sees something he likes, he looks for a person who knows about that thing and gets some info on it. Then he later lectures that same person on the knowledge he had shared, acting as if he is the expert. He thinks he is never wrong. He is right and the rest of the world is wrong. All the people around him know less than the topic they specialize in than he does. If he declares a thing to be good, it is, and you just don't know anything about it. If he says that it's bad, then he's right too. Your opinion doesn't matter, since you're stupid. If you don't like something he likes, you are coarse and your tastes are lowly. If you like something he doesn't, then your choice is poor. He'll never admit he's wrong, he's never bad at anything, even if someone beats him at something. Whenever he sees someone he likes, he instantly copies that person, even if he's ridiculing himself with the attempt.
That's a narcissist for you.