Back in the 1940s, people were sleeping on average just a little bit over eight hours a night, and now, in the modern age, we're down to around 6.7, 6.8 hours a night.

If you look at how humans tend to want to sleep, it seems to be either, you know, sort of a monophasic way or at least a biphasic way, where there's, perhaps, a long bout during the night and then maybe a siesta-like pattern during the day.

Midnight is the time when we think, 'Well, we should probably send our last email; let me just check Facebook one more time.'

Matthew Walker Quotes