Isn't it strange how our internal alarm clocks are so often right-on? Lately I've been leaving the computer from 7 to 10 pm for my daughter to use. During those three hours I like to lay down and relax. Well, since I'm fifty now and stay up all night most of the time, this is reasonable... so I lay down at seven, fall asleep, and suddenly just before ten every evening I wake up... via internal alarm... not a physical one. I think it is just amazing. So far it has always worked just fine for me.