Learning crests during waking hours, giving way to sleep at the moment of diminishing returns, when prolonged wakefulness is a waste of time. Sleep, then, finishes the job. I’ve always loved my sleep, but in the context of learning I assumed it was getting in the way. Not so. The latest research says exactly the opposite: that unconscious downtime clarifies memory and sharpens skills—that it’s a necessary step to lock in both. In a fundamental sense, that is, sleep is learning.
