Periods of high alertness, supported by factors like epinephrine release, should be utilized for learning.

“So don't give up that period of time for things that are meaningless, useless, or not aligned with your goals. That'd be a terrible time to get into passive observance or just letting your time get soaked away by something. That is a valuable asset, that epinephrin, released from your brainstem is going to occur more readily at particular phases of your 24-hour cycle than others, during the waking phase of course. You should know when those are.”