What does it mean if a guy stares at you and then...?

stops after a while? we don't really talk b/c we don't have the same cles, but whenever we see each other hes smiling at me a lot and he stares at me whenever im near (or so i think?) so, does he like me or am i dreaming? he is smokin hot and has a great personality. nowadays he stopped coming to school but sometimes i see him afterschool, and hes still staring at me. even though he is one of the popular guys, he didnt come to the annual dance. hes really shy and we odnt have the same cles so we dont really talk. and he doesnt even come to school? what do i do?