I think bullying is a stupid thing done by troubled people who can't deal with themselves and their own lives, so they try to make others miserable just so that someone feels worse than they do. Or perhaps they can't bear the thought of someone else being different from them, which is just as stupid. But then again, I can't really know what bullies think, since I've never understood them. Even after some former bullies matured, I asked them why they did it and none of their answers made sense to me.
As for me, of course I'm not perfect. No one is. But I've never been a bully. I was bullied many times and I know how it feels, I wouldn't inflict that upon anyone. I have hurt others by accident, I've blown things out of proportion many times, and as a child I even kept away from another child because he looked so ugly that I found him creepy. And I got into many fights before I turned 15. But I've never felt the need to gang up on someone or hurt someone in any way if that person hadn't hurt me or anyone I cared for.