Why won't she forgive me?

It more than likely means she's sick of your acting immature. It's just inappropriate and immature to dump worms on someone's head, trip them, and put dead fish in their locker. I don't know why you think you're so good where you can do stuff like this and then kiss her. No one likes being bullied like this and as many said, what goes around, comes around. The fact that you'll just do this without regret is beyond me. Apologizing means little if you're going to do it again when your friends are around. If you want to be so deceptive and mean to someone, don't expect her to ever talk to you. Before you think she should automatically forgive you, think if this were you. Would you easily forgive someone after doing all this? Be careful of what you do because what's funny to you isn't funny to her. Grow up though. It's nothing funny about talking about someone and harassing them. Hope this helps.