@Pangloss,
I think a big difference is being lost here.
Teasing and crap like that is different than bullying. Bullying is threatening behavior that goes beyond the minor taunting and teasing that can be ignored. Bullying is when teasing because threatening behavior.
Teasing is not good behavior, but like some said, you sorta gotta learn how to handle it and get through. That is behavior you should stand up to and/or ignore or avoid if possible.
Bullying is different - it is mean, threatening and violent. It crosses the line.