Reasons to drink coffee at 10.30pm:
1. I promised myself that I would read 100 more pages today
2. I may as well just finish the whole book at that point
3. I live by a strict moral code, called Bookido, which requires me to start the next book in the pile straight away.
4. Coffee will give me good dreams. Ask any scientist.
5. I have a work assignment due tomorrow morning. That can probably wait though...