Unfortunately I don't have the references to back this up but it's my understanding that the latest understanding of sleep, and sleep in humans, is that we're n

Unfortunately I don't have the references to back this up but it's my understanding that the latest understanding of sleep, and sleep in humans, is that we're naturally biphasic, one long period at night and one short period in the afternoon, and this is what you find with communities today that live as hunter-gatherers. Slightly less "natural" is the monophasic pattern most people follow, which is sleeping at night. I'm not sure what words to describe that waking in the middle of night pattern as other than fad or historical myth—there's no evidence that it's healthier or beneficial given our understanding of the various systems that drive sleep and waking, and evidence for its occurrence is very limited. Indeed it's odd to think that given everything we know about human physiology, that we're all tuned to wake up in the middle of the night, y'know, to do important stuff just without our eyes.