What does it mean when a guy stares at you all the time but refuses to talk to you?

Obviously he thinks you're very very pretty and he has somewhat of an inferiority complex when it comes to talking to girls like you. He's afraid. Believe me, I know. I was one of those guys in high school. Why he stopped? Strange indeed. I don't know. Maybe he's seen you with some other guy and he's afraid you're going to tell this other guy and he's going to end up getting beat up or humiliated in some way.