There are men I know who can wake themselves at any time to the minute. They say to themselves literally, as they lay their heads upon the pillow, “Four-thirty,” “Four-forty-five,” or “Five-fifteen,” as the case may be; and as the clock strikes they open their eyes. It is very wonderful this; the more one dwells upon it, the greater the mystery grows. Some Ego within us, acting quite independently of our conscious self, must be capable of counting the hours while we sleep. Unaided by clock or sun, or any other medium known to our five senses, it keeps watch through the darkness. At the exact moment it whispers “Time!” and we awake.

…In my own case my inward watchman is, perhaps, somewhat out of practice. He does his best; but he is over-anxious; he worries himself, and loses count. I say to him, maybe, “Five-thirty, please;” and he wakes me with a start at half-past two. I look at my watch. He suggests that, perhaps, I forgot to wind it up. I put it to my ear; it is still going. He thinks, maybe, something has happened to it; he is confident himself it is half-past five, if not a little later. To satisfy him, I put on a pair of slippers and go downstairs to inspect the dining-room clock. What happens to a man when he wanders about the house in the middle of the night, clad in a dressing-gown and a pair of slippers, there is no need to recount; most men know by experience. Everything—especially everything with a sharp corner—takes a cowardly delight in hitting him. When you are wearing a pair of stout boots, things get out of your way; when you venture among furniture in woolwork slippers and no socks, it comes at you and kicks you. I return to bed bad tempered, and refusing to listen to his further absurd suggestion that all the clocks in the house have entered into a conspiracy against me, take half an hour to get to sleep again. From four to five he wakes me every ten minutes. I wish I had never said a word to him about the thing. At five o’clock he goes to sleep himself, worn out, and leaves it to the girl, who does it half an hour later than usual.

— Jerome K. Jerome, Three Men on the Bummel

On Saturday morning, I woke up at around 3:30 with intellectual labor pains. A few loose ideas that had been quickening in my brain earlier decided they were fully formed and ready to go, so I had to get up and give birth to that morning’s post. I was a little tired later on, but it was worth the sacrifice.

This morning, I was again awake around 3:30. Yesterday we had been down in North Carolina, and at one point, getting back in the car, I dropped my wallet and it bounced just underneath. I had to get down on my knees to reach under and get it, but it was fine. Nothing fell out. Still, apparently there was some lingering trauma, because twelve hours later, my brain was absolutely convinced that I had either left my wallet or at least some important contents from it in a parking lot in Greensboro. I managed to subdue the fear without having to get up and check on my wallet’s well-being, but of course, my brain was like, “Hey, since you’re up, here’s all these other vitally important matters I’d like to bring to your attention!” Needless to say, none of them were even slightly important. I refused to negotiate and eventually fell back asleep.

If my Garmin wrist device is to be believed, I only get about forty-five minutes of “deep” sleep per night, with another two to three hours of REM, and the remaining four-plus classified as “light.” That seems accurate to me. I do seem to have the ability to set an internal alarm clock, and it doesn’t take much to wake me up. Most of the time, I fall back asleep just as easily, but the problem is that it only takes a couple instances of my inward watchman’s anxiousness to turn into a self-fulfilling prophecy. I think to myself, “Man, I sure hope I don’t wake up with my brain on fire at 3:30 again.” He incompletely overhears that and thinks, “What’s that? A request for another 3:30 wake-up call? Great! Let me just gather up all these vitally important notes I’ve been taking for the last month for tomorrow morning’s meeting…”