I used to sleep an hour or two at night and go all day. I'd do it for weeks at a time. I can't do that anymore though. Unless I get 5 hours, I can't function. It's strange though. If I get less than 5 hours or more than 8 hours of sleep, I'm so tired when I wake up that I can't even live. Even if I sleep for 18 hours I feel more rested if I sleep 6-7. :unsure: