What makes you a likely target?

For being pantsed or given a wedgie, when I was in school all my friends seemed to think it would be funny to pull down my pants or give me wedgies, regardless of whether or not I had basketball shorts, jeans, or sweatpants on, even if I had a belt and I had b-ball shorts on underneath they would still manage to get me, until a couple years ago when we met a new guy and all of a sudden he's the one who gets pantsed and wedgied, I'm only a little bit bigger than he is, and we're both very popular so what exactly makes someone a target.