Thought I am over him but what am I kidding?

Okay, so I moved to Birmingham, fell in love with somebody better. Lat night when I was watching a movie with my parents, I thought about this Atlanta guy. Okay,so here is some information. I met him at the pool, still lifeguard but somewhere else. So, we once hung out, said he would see me again, in two to three months. Later, he got a girlfriend, she forced him to block me off facebook and now I think he is single, but now we are not friends at all. Why do I still fell this way about him? Also, there is a thing in Atlanta called "Lemonade Days" which is a carnival, I want to see him but... Also, when I ran into him last year he was with my friend, but we talked and he thinks I am a stalker. Ideas?! Why do I still feel this way about him?