Guys: Why would a guy avoid a girl?

Okay I used to like this guy back when I was a freshman in high school, i sent him a friend request over the summer and he never answered nor declined it, and i canceled it. I moved on and saw him everywhere my sophomore year. I thought it was pretty obvious that I liked him, but i never stalked him nor talked to him or stared at him.

Now I am a Junior and hes a Senior. I don't even look at him nor see him anywhere. But there's these times when we accidentally see each other and he starts getting fidgety with his hands. Or today I was walking towards class since I was late and he was sitting by himself on a rail texting. I just pretended I had not seen him and the moment he saw me i swear he got off the rail and walked the complete opposite direction of me. Does he think I am a freak, because I have never done anything to him. I am very apathetic about this but that hurt. If he doesn't like me he could just tell me. Then we make accidental contact and he wont stop looking at times, i just look away. There was these moments when I would wear a skirt to school and he would just check me out making it completely obvious. But he avoids me, and i dont know why. I get him the friend request i sent him might have freaked him out, but that was two years ago! I dont even look at him or talk to him or follow him.