Why can't I sleep till at least 5?

So the past week or so I've been unable to sleep till about 5 am. I play WoW till about 1 or 2 a.m then I relax/surf the web before going to bed. I'm 15 and I don't drink caffeine and don't have much of a social life so I don't get outside with friends much. I only have 1 hobby in the summer which is astronomy and that requires little to no activity. Is staying awake all night and surviving on caffeine till the next night a good idea? 10 points for best answer.