The Low Tide

Most of your answers point at the body. This is the cheapest of the four paths to investigate and by a distance the most often skipped, because the causes are unglamorous and because the experience from the inside is not "I am hungry" or "I am in pain" — it is "everyone is being intolerable today". The mis-attribution is almost automatic. The body lowers the threshold silently and then you look around for something to blame, and there is always something available.

The list is short and specific. Food and blood sugar first: meals that slipped, long gaps, breakfast skipped and lunch eaten standing up, and the particular late-afternoon collapse that a great many arguments happen inside. Pain next — not dramatic pain, the ongoing background kind that you have stopped consciously registering, which is exactly the kind that costs the most, because the effort of ignoring it is drawn from the same account as patience. Then hormones, and this is not a women's item, though a cycle is a real and well-documented one that deserves to be named rather than joked about: testosterone moves, thyroid function moves — an over- or underactive thyroid produces exactly this picture and is found with one blood test — and the perimenopausal years produce it too and are routinely attributed to stress for years. Then caffeine, where the story is the rebound rather than the coffee: more of it to cover a bad night, and a harder dip in the hours after each one. Then alcohol, where the relevant day is the day after. Then medication, which deserves more suspicion than it gets — irritability is a listed effect of a surprising number of ordinary things, including some common cold and decongestant preparations and anything steroid-based, and it is worth asking a pharmacist rather than guessing. And finally the plain one: the day or two before an infection announces itself, when everyone is inexplicably unreasonable.

The line worth taking away is this one: before you attribute a change like this to your character, rule out this path, because it is very much cheaper. Character work is slow, expensive and uncertain. Eating something before the hour it is usually worst, moving the last coffee three hours earlier, and looking at what started in the same month the irritability did are cheap, fast and testable within a fortnight. If something on that list turns out to be the answer, you will have saved yourself a long detour into thinking you had become a worse person. And if there is pain in the picture, or anything that sounds like it could be thyroid or hormonal, that is ten minutes of a doctor's time and one blood draw — which is a small price for closing off a whole branch of the question.