When I was a kid I remember my mother used to scold me if I left my textbook open and went to bed. She explained that if you keep your textbooks open for too long Lady Saraswathi would punish you for this.
For the curious lot: Lord Saraswathi is the Goddess of Wealth and Knowledge in the Hindu religion. So those days I figured She might not like it if I left the books open. Although I never really understood the actual reason behind it, I used to think this and dutifully close my books and go to bed.
Nowadays I have to say that the times have changed a lot. Today when I logged-in to my onsite machine and upon noticing so many open applications in the taskbar (pending work) I also seemed to notice a few RQSDs (Requirement Specification Documents) opened in MS Word and went...OMG!!!