Aye, I was challenged to fights my whole childhood, I was in so many fights I couldn't begin to put a number on it....but I was never a bully.
What you need to be careful about is becoming a bully yourself, and make sure you are not kidding yourself on that you are being honorable, when all you are really doing is throwing your weight around against someone, just because you don't like them.
eg....let's say one guy calls another guy a d*ck, for no reason...he says it to him over the phone, or over a computer screen...and the guy who was insulted calls him out and says he wouldn't have the guts to say that to his face, in other words, he's calling him a cowardly bully with a big mouth he couldn't back up in the real world.
So, you charge up and threaten the guy who was called a d*ck with physical violence, because you think the guy is a d*ck as well....that would make you the bully, in my eyes.
The guy who started that sh** up by calling the guy a d*ck for no good reason, a grown man no less, if he wants to start talking like that, he can answer for himself. Because he needs to learn that he can't just go about abusing folk and think they are just gonna take it lying down. He was the bully in the first place as well.