Who needs an alarm?

My infernal internal clock seems unabated no matter what actions I might take. Staying up late (on multiple occasions) seems to have little impact; bad (or good) dreams are similarly unimpeding. It's a strange feeling, to wake up at the normal time when hoping to sleep in, especially when on so many occasions my mind is reasonably alert but my limbs are still hoping to stay relaxed and undisturbed for an indefinite period. Perhaps that's an indication that yesterday I tired myself out what with driving and classes and running up stairs with lots of books and cleaning and pickup (hooray) on the turf, but didn't bother to think hard enough all day. The mind needs 6 hours, the legs need 8. But despite my initial alertness, by now I'm feeling fuzzy in class, my fingers are slow (and incorrect) on the keyboard, and I dread the afternoon lecture with dim lights, slides, and a quite soothing voice. It doesn't quite seem fair.