Former bully, checking in.
But really I was never bullied growing up, I was always the one doing the pushing. I spent a lot of time in detention, this was from pretty early on, 3rd grade or so until about 7th. By then I already had the reputation among my classmates. Small town, so I went to school with the same group of people from the start basically. In those early years I was very much a physical bully, I'd get into fights just to get into them really. I don't remember there being an actual cause, of course it was a while ago so it's possible I've just forgotten. But for the remainder of middle school I just stopped really caring about the whole bullying thing.
My freshman year in high school I wore a long coat for the first few weeks, not a trench coat per sey but close enough right after the whole Columbine fiasco perpetrated by the 'trench coat mafia'. Let me just say, wow those halls were clear, I could find my classrooms without a problem.

I will say though looking back on those years now I remember anger being one of the only things I really felt like I experienced fully. Perhaps that's why I went all 'dark side' and became a bully.
Even now, though I'm much more withdrawn than I was when I was younger, anger is still the one emotion I feel like I'm actually drawn into. Joy, sadness, etc I always feel detached from them, as if I'm watching them happen to someone else. Granted I was also an incredibly bizarre child from the start anyway, I'm told as a baby I cried when people picked me up, left alone I was quiet and just fine. So perhaps those emotional wires have been crossed from the start versus anything to do with my environment.