Why does he want me when we are total opposites?

theres this one frat guy at my collegfe who is always trying to get with me. We have different sets of friends at he is what one would call the sterotypical douche..where as I am the nice, friendly, kinda awkward girl (but i do party)...he keeps calling me at 3 in the morning to hang out aka call when he ignores me in public and he's been trying for the past 3 months..with not really any success. what i dont understand is why he is doing this when he told me there are tons of girls he could hang out with but hewants to hang with me...i dont buy his bs im just curious as to why he can't call one of the girls from his crowd.