Why did this boy I used to talk to delete me off facebook?

So a while back I used to talk to this boy, for a while. But didnt date because I'm not aloud to, I saw him in school. We stopped talking bcuz I thought he was a bit of a jerk, and I feel like he just had major issues going on in his life, and I couldnt deal w/ the way he would act. He has huge spaz attacks and freaks out alot. I have anxiety and get paranoid also, but not as badly. Whenever he got mad at me, he would RUN out the class for 10 minutes and come back with a bag of chips.............anyways, we dont really have any classes this year (junior year) so we dont talk. Only on facebook rarely.... He got a girlfriend, but I still thought about him every now and then. I like another boy now, but for some reason, this crazy boy I used to like, cant seem to leave my thoughts lol. Well everytime him and his gf fight /break up, he im's me on facebook. I feel like I'm his "2nd person" just incase he becomes single? Its retarted... lollllll I deleted him twice a while ago, bcuz I wasnt over him and was tired of the "only im me when u break up with ur gf" thing but readded him when I got over him......a couple days ago, he liked me newly uploaded default, and today i wanted to creep on his profile, and he deleted me? WHY do u think he deleted me? I dont get it..............