Sleep patterns have a way of shifting in my later years. Publicly available YouTubes delve into some of this. Sleep trackers of dubious accuracy exist as phone apps next to a pillow and as watch features. I've used both. Sleep hygiene advice exists online from multiple sources, most pretty consistent. Go to bed at a fixed time, arise at a fixed time, don't fidget indefinitely in bed when awake. Getting up and reading results in sleep deprivation the next day. And avoid the bed during the non-sleep times.
Some predictability emerges. For me, it's lights out at 10PM, unless my wife is reading. Shades down. Bedroom and bathroom doors nearly closed. Room cool with window AC if needed. Its noise does not seem a deterrent to sleep. Phone and laptop off at 9:30. In bed with basic Casio watch, set to notify me at 6:50, which I mostly do not notice, and with wife's clock radio set to a classical station at 6:48AM. So far, so good. I'm rarely agitated in the evening as a source of initial insomnia. I've learned to mark the end of each day: three things that went well, one that did not, and three sources of gratitude. Then lights out and into oblivion within minutes, with a short recognition of my wife's arrival an hour or two later most nights.
Middle-of-night insomnia has gotten predictable, typically at 3AM. One reason I prefer Casio with no apps to my Tozo 3 with sleep tracker and countdown timers and heart rate record is its inclination not to look at it when I conclude my first sleep phase. Sometimes I can see the electrical numbers on the alarm clock, sometimes not. A quick illumination of the Casio reveals the time. Not invariable consistency but most often within an hour of 3AM.
YouTubers claiming expertise offer explanations, few provable, and solutions, none effective for me. My guess is that my primitive brain takes over. Sleeping through the night seems a recent addition to human behavior. In hunter-gatherer or early community eras, the night presented as two sleep times. Nature determined darkness, with a hormonal mechanism to adapt. Dawn determined awakening. And about mid-way between, people got up to spot-check danger. Later in the early communal phase, people took turns as sentries, covering overnight shifts. We employ people in that fashion today in our police and medical teams, but we move their assigned shifts, keeping them the same length. So there is a physiological explanation, along with some hormonal and medical ones. A few tries at melatonin otc did not change that. Dr samples of Ambien did, though I have no interest in medical manipulation of sleep with a stable pattern established that does not leave me impaired when my OOB time appears.
That second half of most nights appears in a minor transition. Returning to sleep has also established predictability. It takes just over an hour most of the time. I rarely feel edgy or an inclination to make myself productive, in effect creating a second nocturnal work time. Some nights I think about activities of the previous days or decision dilemmas. I recognize some impasses as solved from having slept on it the first half of the night, but I do not keep a pen and paper next to the bed to record what I think. On rare occasions, a dream awakens me, more often a nightmare with distortion of the familiar than a sleep hour of REM ecstasy.
The interval of night's second half seems recently different. My ability to doze off again has gotten less predictable. When I do, the second half rarely brings me to my assigned wake time. I can expect a second awakening about an hour or so before the scheduled clock radio brings my ear some measures of a symphony and my Casio chimes a minute or two later. At the second awakening I rarely feel ready to arise earlier than the alarm. Most often I lie quietly, glance at the clock or watch periodically, then arise when I intended to. That part goes well. What does not are those nights when I only stay awake for minutes on the second arousal, drift back to a deeper stage of sleep in that final hour, then get an unexpected jolt from the radio's timer. I rarely feel motivated to emerge from bed under those circumstances, though I will mostly keep my commitment to myself, and to sleep hygiene advice to get up and proceed with dental hygiene, irrespective of how I feel. I almost always adapt once I see daylight through the bathroom window and complete the session with my electric toothbrush. Then downstairs, go outside to retrieve the newspaper from the end of the driveway, and let natural light reset my intrinsic patterns.
Might I feel better, or at least have a longer duration of energy through the day, if those overnight interruptions disappeared? I don't know, though in late life I do not feel energy deprived. I am able to recognize the pattern on my own, without the aid of an electronic device. Polysomnography might determine cause, though I suspect my sleep pattern will differ in a semi-public space hooked up to wires and sensors than it does in my own bedroom or a hotel. Not worth the effort, though I sometimes wonder how much more energy can come my way with small tweaks in the things I habitually do.
For now, my pattern, while not optimal to the YouTube gurus or the sleep advocacy organizations, gets me by. No reason to change my current circumstances.