Long ago, when humans lived by daylight, we likely lived this way, with a "hole" in the middle of sleep, where people would wake up, putter around, chat and tell stories, have something to eat, and then go back to sleep. There was a lot less going on back then, people didn't have access even to books and candles were costly anyway so there was no reason to stay up late. I've had the same issue myself although these days, it's just the 2 times to pee.