What I really don't care for are people who enjoy the hell out of street fighting. They look for fights, and always find them. I pretty much understand their physiological background and quirks, but I do not have much apathy, nor tolerance, for them. In any protective services field, or in police work, you run into these people on a pretty regular basis. When you tangle with them you are trying to control, they are trying to hurt. It's always a pain in the butt.
It sucks when you cross paths with them in private life. And if you're well trained it still sucks, because you're supposed to be above all that.
But it must suck really bad to actually be them.