"Predetermined Autonomous Sleep Termination"? Who thought up that name? Well anyway it happens to me a lot and has been for years. I've found that when I was younger, if I had to be up at 4 AM to catch a flight, I'd set my alarm for 4 but actually wake up at 3:55. I'd simply turn off the alarm (before it sounded) and head to the shower. Now that I'm older in the same scenario, when I awaket at 3:55, I'm ****ed that I could've had 5 more minutes of sleep

. Anyway, it happens to me all the time, just never knew there was such a fancy name for it.
Michael