Why do people stare at me?

I'm not even going crazy, I'm walking home from school and legitimately see people staring out of their car windows just looking at me walk. I don't walk weirdly as I've never had anybody tell me and I don't consider myself particularly ugly, but they're certainly not looking at me as if I'm handsome. I wore sunglasses the other day so people didn't turn away when I looked, and about 70% of people were looking right at me...

Is there any reason to this with what I've told you?