>Does the 90-minute cycle mean that so-called power naps are worthless? “They can take the edge off basic sleepiness. But you need 90 minutes to get to deep sleep, and one cycle isn’t enough to do all the work. You need four or five cycles to get all the benefit.
Notice, my sleep pattern contains 3 full cycles a day. And less time between cycles.
I'm not just subsisting on short naps.
The second link simply confirms what I initially said, that sleep is a cleaning cycle for the brain.
You can totally lose symptoms of tiredness, only to wind up with dementia at later point in life.