Recent quotes:

Want to enjoy the deep, mystical sleep of our ancestors? Turn your lights off at dusk. - The Washington Post

You have to be willing to revert to a Paleolithic pattern of sleep — and that means turning off your electric lights at dusk and leaving them off until dawn. Do that, and in about three week’s time, beginning around six hours after sunset each evening, you will find yourself experiencing a period of serene wakefulness that was once a nightly meditation retreat for all Homo sapiens on Earth. It’s a guarantee. It’s encoded in your genes.