Evidently I'm no longer capable of sleeping more than about 6 hours in one stretch. I'm not well-rested after these 6 hours, mind you, but I am awake. Last night I went to bed around 1:30; this morning I was awake around 7:30 even though my alarm was set for 9. A similar thing happened yesterday, too... But yesterday, after being up for an hour or so, I went back to bed for another hour, hour and a half of sleep. But I can't go back to sleep right away - after all these years of sleep deprivation and napping to catch up, I seem to have trained my body not to expect anything more than 6 hours. In some ways, this is useful - when I can only get 6 hours, it's nice that my body is reasonably alert. It's bad in other ways, though - namely when I could get more than 6 hours, I can't. At least not without an hour of reading or something before crashing again, anyway.