According to an article I saw on HN a week ago, apparently, evidence shows we evolved to naturally wake up once each night about half way through, for around an hour. Of course, we went to sleep when it became dark and woke with the sun. Something that isn't conducive with todays lifestyle.
I've seen the "first sleep" references too. That's not what I'm talking about. Waking up naturally for a half hour in a pleasant relaxed state is one thing. Having the dog bark "let me out or I'm peeing on the carpet" and having to run downstairs, having the other dog jump on me at random intervals, having two kids separately get me up for a half hour each fussing about whatever, and having m'lady decide she must check her email at oh-dark-thirty, well, that's quite something else.
