For me, it has everything to do with consistency. Then my brain adapts and is not in deep sleep when my alarm goes off. Consistency can be the number of hours

For me, it has everything to do with consistency. Then my brain adapts and is not in deep sleep when my alarm goes off. Consistency can be the number of hours asleep or the time I get up, and takes about three days to set in. It gets even better if I break up my sleep into, say, 3 hour chunks; instead of just sleeping for multiples of three hours, I inform my body when it's time to start and stop sleep cycles by waking up for 20 minutes. It is supposedly more efficient because your brain on its own spends longer than necessary in between sleep cycles, which is a waste of time. Just a few more ideas!