I was doing some research into my own sleep problems (groggy again this morning) and learned of Delayed Sleep Phase Syndrome: http://en.wikipedia.org/wiki/Delayed...phase_syndrome. Then I remembered this thread.
I'm reluctant to diagnose myself, especially considering it effects a small portion of the population. But this fits me to a tee. In a nutshell, I want to go to sleep at 4am and wake up at noon. I don't need more sleep and don't feel like my sleep is that poor quality, provided that I get the hours right.
This might fit some of you as well.