The thing that irritates me (like everyone else) is the people you've passed who zoom past at stoplights. I was at a light with two other folks on fixies yesterday, all of us trackstanding, and a genius on a hybrid decides to navigate through us, as if we were road hazards. He nearly ran into me, and did bump the other guy there (he was ok, just had to put a foot down).

Light turns, we all pass him, and the next intersection is stopped for a fire engine...and the hybrid guy tries it again.

A genius, like I said.