I didn't have a problem "standing up" for myself. For me, the problem was more knowing when it was the right time that I SHOULD stand up for myself. There was this gang of about 3 or 5 guys I messed with one time, the ring leader who just drove me nuts one day, so I proceeded to rearrange his face. I knowingly started this in front of a classroom because it wouldn't take long before the teacher came out to break it up. Those guys verbally pushed me around about a week or two after that, but they knew good and well they couldn't start anything with me. Besides, do YOU want to mess around with the CRAAAAAAZY dude?
There are those more conniving passive-aggressive individuals that were more adept at getting people in trouble because there was just SOMETHING about them, you can't put your finger on it, but they just piss you off so bad you WANT to beat the $h!+ out of them. The trouble, though, is YOU'RE the one who's gonna be caught and get in trouble over it while the other person is the one who gets the last laugh. See, I should have been THAT guy, I just wasn't smart enough or quick enough to put it in practice. But when I was going through my clueless junior high phase, I didn't feel quite so bad about dealing with NT bullies by at least getting in a few licks. I started taking more crap later on because fights at my school got bad enough that administrators HAD to crack down on them. Don't like it? Transfer to the PUBLIC schools! Yeah, rich kids can be brutal. But man, oh man, I wish I could have been THAT guy who got someone kicked out of school, all because I was willing to take a few bumps and bruises.
But on the other hand, I did have a few very sweet NT friends in my class that, even if they didn't understand me, they at least were supportive. In the end, I think it was being nicer to certain people that kept me out of trouble more often than in it. They would have known right away if I'd been doing the whole "psych-out" thing, and I don't think they'd have had as much respect for me if I'd been that way. Nobody likes you if ALL you do is huddle in a corner in the fetal position!