What does "douche bag" mean?
someone called me that and idk what he means by it.
A douche bag is a term used to refer to an arrogant or obnoxious person. Some people just use it in a weird way so that they can make somebody angry. Go to http://www.urbandictionary.com/define.php?term=douchebag for reference.
IT means a very rude person
A it who thinks he is "all that" and only cares about himself
Full of himself, often a player, obnoxious guy. he could have been joking around tho, people use it pretty casually.
You have some good answers already. It does mean all those things, and also means "dumb", and "stupid" sometimes.