=Thinking in Circles.= Habit means automatic, subconscious activity, with the least expenditure of energy and the least amount of fatigue. We have already noted the ease with which heart and diaphragm muscles carry on their work from the beginning of life to its end. Anything relegated to the subconscious mind can be kept up almost indefinitely without tire, and to this subconscious type of activity belong the thoughts of a chronic insomniac. Despite all assertions to the contrary, his conscious mind is not really awake. If he is questioned about the happenings of the night, he is likely to have been unaware of the most audible noises. The thoughts that run through his brain are not new, constructive, energy-consuming thoughts, but the same old thoughts that have been going around in circles for days and weeks at a time.
It is true that a person sometimes chooses to wake up and do his constructive planning in the night. This kind of thought does bring fatigue, up to a certain point. After that the body hastens its rate of repair or automatically goes to sleep. Activity of this kind is always a matter of choice. He who really prefers sleep will shut the drawers containing the day’s business and leave them shut until morning.
=Day-Dreaming at Night.= However, the man who makes a practice of staying awake rarely does much real thinking. He lets the thoughts run through his mind as they will, builds air-castles of things he would like to do and can’t, or other kinds of air-castles about the disastrous effects of his insomnia on the day that is to come; he worries over his health, or his finances, and grieves over his sorrows. He is really indulging himself, thinking the thoughts he likes most to think, and these consume but little energy. Like a horse that knows the rounds, they can go jogging on indefinitely without guidance from the driver.
=Tossing and Fretting.= The thing that tires is not the insomnia but the emotion over the insomnia. If people who fail to sleep are perpetually fagged out, it is not from loss of sleep, but from worry and tossing. Often they spend a good deal of the night feeling sorry for themselves. They turn and toss, exclaiming with each turn: “Why don’t I sleep? How badly I shall feel to-morrow! What a night! What a night!” Such a spree of emotionalism can hardly fail to tire, but it is not fair to blame the insomnia.
He who makes up his mind to it can rest almost as well without sleep as with it, provided he keeps his mind calm and his body relaxed. “Decent hygienic conditions” demand not necessarily eight hours of sleep but eight hours of quiet rest in bed. Tossing about drives away sleep and uses up energy. I make it a rule that my patients shall not turn over more than four times during the night. This is more important than that they should sleep. To be sure, I do not stay awake to enforce the rule, but most people catch the idea very quickly and before they know it they are sleeping.