I'm a natural night owl, and was able to indulge that when I was in college -- I scheduled all my classes for past 1:00 PM, and just stayed up until I wanted to. I frequently was up until 3 or 4 AM.
I really hated the whole "unsavory" aspect of it, it bothered me a lot. I got the same amount of sleep as anyone else (usually around 8 hours), I was an excellent student, I was working for much of it (1-5 PM), I didn't do drugs, etc., etc.... my schedule was just shifted
a little bit. But people were often kind of icked out by it.
When I started working full time I had to do an abrupt schedule shift, and I was able to, I just didn't like it. (Woke up at 6 AM.)
When I became a mom, the schedule shifted again -- whether by nature or nurture we're all night owls. E.G. makes his own hours but they would frequently be LATE, so we'd be having dinner at 9 PM and then going out for a post-prandial stroll in the dark. The interesting thing is that we'd see a lot of Indian families out there, complete with babies. Not sure what was up with that, culturally. (Co-sleeping?) Anyway, among mainstream whitebread Americans that was very weird.
That continued 'til kindergarten, when sozlet had half-day afternoon and we had to rush a bit to get her there by noon.
Then first grade (all day) was a big shift, and it was sucky. But it worked, and we're all currently on a more-or-less normal schedule. (Wake up at 6:30 AM or so.) I expect that once she's in college we'll all revert.