I THINK I’VE BLOGGED ABOUT THIS BEFORE: The Forgotten Medieval Habit of Two Sleeps. “And far from being a peculiarity of the Middle Ages, Ekirch began to suspect that the method had been the dominant way of sleeping for millennia – an ancient default that we inherited from our prehistoric ancestors. The first record Ekirch found was from the 8th Century BC, in the 12,109-line Greek epic The Odyssey, while the last hints of its existence dated to the early 20th Century, before it somehow slipped into oblivion. How did it work? Why did people do it? And how could something that was once so completely normal, have been forgotten so completely?”