I'm a night owl. I think it started while playing World of Warcraft when I was 12/13 years old. To join guilds and to gain experience, you had to play late (i.e. past 00:00) and you kinda wanted to, because the game was fun as hell. It continued through high school and college, even if I had stopped WoW. I never had a semester with "clean hours", that means where I start everyday at the same hour. It's been nearly 10 years that I didn't go to sleep before 00:00, with its consequences. I tried several times to change habits to wake up early, but without "clean hours", it's really hard. So for now, I stay awake till 1-2 am and have to wake up at 6:40 if college start at 8, or wake up at 10:40 if it starts at 12. I will try again to be an early bird when I finish college.