Got to be careful with that; extremes at both ends (not sleeping and sleeping well) shouldn't, in general, be used too frequently. Hence, the ideal balance of sleep and awake. Though, I've found that if you have something with caffeine in it while you're trying to pull an all-nighter, space the caffeine consumption out between 2 and 3 hours per unit of caffeine. This way, the caffeine you'd previously ingested will be fading by the time you ingest some more; works like a charm for about 10 hours, and then caffeine doesn't seem to have much of an effect anymore.
Sleeping for 15 hours, though, probably requires mass quantities of prescription sleeping pills (Ambien, et al), combined with a day thats ending after dragging on and on for 18-22 hours and beyond..
You have never heard of The White Stripes!? If you believe in any sort of god make sure to thank him/her/it next time you are having a personal moment with them.
Sleeping for 15 hours, though, probably requires mass quantities of prescription sleeping pills (Ambien, et al), combined with a day thats ending after dragging on and on for 18-22 hours and beyond..