(This photo has very little to do with the post other than that 1. I'm sleeping in it and 2. Aw.)
Thanks so much to reader clairebecca for sending me the link to this article on Biphasic Sleep, which was both generally interesting and made me feel loads better. And many of you have written to me that you have similar problems, so I thought hey: maybe it'll make you feel loads better, too.
(To recap, in case you missed my earlier posts on the topic: more nights than not, I suffer from something called "habitual waking" where between the hours of about 1:30 and 4:30 I wake up repeatedly, and am sometimes am unable to fall back asleep for hours, if at all. If you've never dealt with this, it may not sound like a big deal, but honestly, it's pretty miserable: after a certain point you start panicking, which only makes the situation worse, and while some things help a little - including turning clocks away and keeping the room cool - I have yet to find anything reliable.)
Anyway, I found this article fascinating. Basically, what it says is that we didn't evolve to sleep eight straight hours: we evolved to fall asleep when the sun went down, spend the nighttime hours in total darkness (not the city/suburban yellow-ish glow of today), and go through a biphasic cycle, in which 3-4 hours of "deep" sleep are followed by a second phase of "morning sleep".