Certain people who feel the need to put others down.
I absolutely detest that characteristic in someone.
The ones who say they will do something or are happy to do something with me and then don't do it and then they get all upset when I show them prof that they did in fact say that when they say they never said that and I tell them how disappointed I am with them and then they dump me.
Then again I should be happy they did me a favour and showed their true colours before I got to involved with them.
I don't think it is any one thing..more like a cocktail of things..except one of those cocktails that makes your nosehairs feel like they're going to burn off..not the good ones :P
Yap yap yap yap yap. Lets just hear me talk all day types :)
Boring old stupidity.