I used to have huge sleeping problems a couple of years ago (after my first year at college). At the beginning of the summer and the beginning of my 'lovely' month of exams I stopped sleeping. It was 24-72 hours at first, which ended with me failing most of my exams and was supposed to go to the re-take exams in September, but by the fall my insomnia had got quite bad, if I didn't sleep for 72 hours I was lucky, because I stayed awake for 5 and more days. Personal record is 9 days. Ended up with failing exams again, being forced to take a gap year at college, lost a lot of weight, my sight got worse, and I ended up in hospital with a broken leg after being hit by a car due to my going out to the store and falling asleep as I walked. :] yep, not fun days. Now I force myself to go to bed even when I'm not sleepy, making sure that at least my body will be laying and resting for 6-8 hours per day.