Would that nobody had told me about the 8 hours thing when I was so young. I pathologically set alarms before free days to currentTime + 8 * 60 minutes and go to bed alarmTime - 8 * 60 minutes, and I feel wrong all day if this is interfered with.

In fact, I find that my body can handle significant variation to the 8 hour rule. Knowing this doesn't help my obsession.