This post and the replies made me think of lots of things--how new parenthood and medical residency are both sort of like the torture @anotherjoe described, how rarely people get to sleep until they wake naturally, and how lucky I am that I rarely have to wake to an obnoxious alarm clock.

I spent miserable years getting up before I was ready--or oversleeping--because I would stay up too late to allow myself adequate sleep. I stayed up too late because it was the only way to get enough quiet time to meet my introvert need, especially when I had evening activities.

Now, it's my body that makes me get up before I'm ready, but I think I wake up in the lighter cycles of sleep, so I don't usually feel super groggy. When I first left the world of employment, I thought, Ah, I'll sleep until 9 or 10 a.m. But horses clopped along the street outside our first apartment, and construction noises echoed off the mountains. Another place was next to a school, and the children hit the playground at 6:30 a.m.

Now, I'm in more rural place, and if I stay up late, the only thing that usually wakes me other than my bladder or lungs is maybe a precious little girl with a high, squeaky voice or my desire to see the volcanoes in the clear morning light.