How I wish I had learned some form of self-defence. However, my mom wouldn't let me learn karate because (a) it was a devil-tainted sport (meditation! The horror) and (b) girls didn't do that. - and I point-black refused to do ballet.
But most bullies will back the hell down if faced with opposition; they really only like to pick on people who don't fight back, because they're actually cowards themselves. Also, I've discovered, bullies really don't like it when people on whom they're picking turn into raving psycho loonies who will attempt to annihilate anything in the vicinity.
Still, I don't pick (physical) fights, on the whole. In fact, I have never picked a fight except with Deafboy (and then I broke my hand on his jaw. That frigging hurt like a bitch, but I was too proud to complain, so I left it. At least it seems to have healed okay). But I do have an unfortunate habit of taking on people most likely to pulverise me; my only real weapon is the element of surprise, or my desire to never be seen exhibiting any form of pain.
Example 1: the bodybuilder I slapped because he wouldn't stop ragging on me, who then punched me so hard I flew over my cousin's bed; he didn't expect a raging ball of fury to come back over the top and take him to the ground (since I was 16 and he was 18, it's probably a good thing my cousins pulled me off him, or I would have been a smear on the carpet once he regained his wits).
Example 2: In Std 4, aged ten, I gained a reputation as Ms Coldheart, because I would not - I would not - exhibit any pain when I was punched, pinched, kicked or had the dreaded "mousie" performed on my arm. These were the bullies who tended to pick on my younger cousin, Greg, who was in Sub B at the time; so I'd take his place in the torture because, come on, he was almost five years younger than us! Naturally he'd cry when hurt! Asses. But all the bullying stopped the day I broke one boy's jaw (I was nearly suspended for that, until my mother pointed out all the bruises and other injuries I'd accumulated from their nastiness. She still wouldn't let me take up any form of karate, though. Sigh).
Basically, I am too belligerent for my own good; I dread to think what would happen were I ever involved in a hijacking, or a home invasion that left my loved ones in danger.