Why does a hot guy sit alone?

[Sarah]

There's this extremely attractive guy in my class. So many girls are attracted to him. But he never pays attention to any. he doesn't have any guy friends either. He sits alone at lunch and looks sad all the time. He doesn't pay a lot of attention in class either but still manages to get highest marks. I know his name and i found him on facebook but he has so much privacy and we have no mutual friends at all. He doesnt even know if I exist, he doesnt know any one in school. Why wont he make fr iends? hes very attractive and wont have any trouble. also should i approach him? I have a huge crush on him but i feel weird aproaching him, what if he sits alone by choice? I also heard him telling a teacher some one passed away in his family, maybe thats why hes like that?