It's funny, one of the things I realized about myself while I was off work for maternity leave was my natural rhythm - my natural state of wake and sleep. I'm definitely a night owl. If I had my way, my preference would be to stay up until at least 1:00 or 2:00 a.m. and sleep until 8:00 or 9:00 a.m. That's what I did for pretty much this whole last year, and it was pretty great - despite the multiple times waking up between 2:00 a.m. and 9:00 a.m.
I just feel like I get more done at night. When the house is quiet I can finally relax and do what I've been meaning to do all day.
Could you imagine what it would be like if everyone could work hours according to their own natural body clock? I suppose it would be terribly inconvenient, but it would also be awesome.