What happens when you don't get any sleep at all?

I often pull all-nighters, I think my very first time pulling an all-night was when I got into the World of Warcraft beta. Didn't sleep for a day and half. I felt like shit though afterwards, and took me a couple of days to recover. Now though I recover just right away really. I'll stay awake for 30-40 hours, go to sleep for like 8 hours and wake up as if nothing had happened at all. The first 24 hours are really easy for me, after that though it becomes a game of me trying to stay active. I start to nod off to sleep but wake up as soon as my head drops, but after a certain amount of time has passed, like 28 hours, I end up getting like this second wind almost always and I'm no longer tired at all. I find it rather weird.

Jam it back in, in the dark.