I hear that. After my hernia surgery a couple years back, I was out of work and free to sleep and wake up whenever I wanted for an entire month. I was going to bed at like 5pm and getting up at 1am. This went on for the entire month I was out of work. Weird thing, I felt great and had a ton of energy. Maybe this is my natural sleep cycle?
Best part was, this surgery was a blessing in disguise because while I was bed-ridden and out of work, I had all the free time in the world... and I discovered this whole affiliate marketing/webmaster thing... and haven't turned back since.
If I wouldn't have gotten that hernia, I'd probably still be hating my life doing the 9-5.