Homily grits

Fatigue can produce extreme gentleness, and quiet of mind, and even something like vision. If you have often seen men led by it into anger, malice and impatience, that is because those men have had efficient tempters. The paradoxical thing is that moderate fatigue is a better soil for peevishness than absolute exhaustion. This depends partly on physical causes, but partly on something else. It is not fatigue simply as such that produces the anger, but unexpected demands on a man already tired. Whatever men expect they soon come to think they have a right to: the sense of disappointment can, with very little skill on our part, be turned into a sense of injury. It is after men have given in to the irremediable, after they have despaired of relief and ceased to think even a half-hour ahead, that the dangers of humbled and gentle weariness begin. To produce the best results from the patient's fatigue, therefore, you must feed him with false hopes. Put into his mind plausible reasons for believing that the air-raid will not be repeated. Keep him comforting himself with the thought of how much he will enjoy his bed next night. Exaggerate the weariness by making him think it will soon be over; for men usually feel that a strain could have been endured no longer at the very moment when it is ending, or when they think it is ending. In this, as in the problem of cowardice, the thing to avoid is the total commitment. Whatever he says, let his inner resolution be not to bear whatever comes to him, but to bear it "for a reasonable period"—and let the reasonable period be shorter than the trial is likely to last. It need not be much shorter; in attacks on patience, chastity, and fortitude, the fun is to make the man yield just when (had he but known it) relief was almost in sight.

— C.S. Lewis, The Screwtape Letters  (The Letters are written from the point of view of a senior devil advising a junior devil on how to tempt "the patient", i.e. the human he's been assigned to.)
 

Delay by delay, as the aggravations and frustrations accumulate, I'm trying to keep this one in mind.