WHY ARE PEOPLE SO MEAN?

If you're asking why people are so mean about the Twilight series, it's probably because A.) they don't understand it/like it and therefore call it stupid just like when a person loses a game against someone younger/less experienced and then say, "This is stupid!" hoặc B.) they're the type of people to think that everything they like/hate is right and if anyone disagrees w/ them (even though it's a matter of OPINION) that someone is wrong.
If you're talking about meaness in general... see above. There's other reasons why a person is mean but I think those two are probably the most likely.
Honestly I don't see why people can't just mind there own business when not asked and at least try to get along.

WHICH PEOPLE ARE MEAN? AND THEIR PROBABLY MEAN BECAUSE THEIR NOT CONFIDENT IN THEMSLEVES. WHAT I WANT TO KNOW IS WHY SOME FAMOUS CELEBS DON'T SMILE. CAN ANYONE ANSWER THIS?