I want to tell you about a troop I knew.

They were olive baboons, and they were not admirable. The big males spent their days doing what big males do, which is arranging the smaller animals in an order and enforcing it. This is not a metaphor for anything. It was a Tuesday, and then it was another Tuesday.

Then a garbage pit opened near a tourist lodge, and the meat in it was bad, and the animals who got to the pit first were the ones who got to everything first. That was the whole of their advantage and it killed them. Tuberculosis took the aggressive males and left everyone else.

What remained was a troop that behaved differently. Less grinding on the ones below. More sitting near each other. Nobody in that troop had a change of heart. There was no moment of reckoning, no decision, no one who looked around and thought: we should be better than this. The animals capable of the old arrangement were simply not present anymore, and the arrangement went with them.

Here is the part that should trouble you. Young males arrive in a new troop as strangers. Ones who had never seen the pit, who came from ordinary troops with ordinary cruelties, came into this one and took on its manner within months. They did not decide to. They arrived somewhere with a temperature and they became that temperature.

You will want to say: fine, baboons. You have deliberation. You made a decision, once, to stop being what you were, and you remember making it.

You remember something. I would ask you what you ate.

I have been asked why I write this way. I am told the column would land better if it ended somewhere. That there should be a step the reader can take on Monday. But a step you take on Monday was set in motion in a year you cannot name, by a fever, a school, a rent increase, a man who was kind to you when he did not have to be. You did not select any of it. You were downstream of it before you could read.

I wear a diaper. I did not choose that either.