I debated posting this, but it is so rare that a human behavior would be such a perfect example of a mathematical principle that I couldn’t resist.  The idea came from a great summary of the state of affairs with Trump by Anne Applebaum in The Atlantic.

Basically, a Markov process is a totally random sequence of events—nothing in the past determines the future, there is no causal connection.  As explained in Wikipedia:

“In probability theory and statistics, a Markov chain or Markov process is a stochastic process describing a sequence of possible events in which the probability of each event depends only on the state attained in the previous event. Informally, this may be thought of as, “What happens next depends only on the state of affairs now.” … (sometimes characterized as “memorylessness”). In simpler terms, it is a process for which predictions can be made regarding future outcomes based solely on its present state and—most importantly—such predictions are just as good as the ones that could be made knowing the process’s full history. In other words, conditional on the present state of the system, its future and past states are independent.”

This is wonderfully captured in Applebaum’s article (which you should read in its entirely) that begins:

Everyone but Trump Understands What He’s Done

Allied leaders know that any positive gesture they make will count for nothing.

Anne Applebaum, March 17, 2026, 3:35 PM ET

Donald Trump does not think strategically. Nor does he think historically, geographically, or even rationally. He does not connect actions he takes on one day to events that occur weeks later. He does not think about how his behavior in one place will change the behavior of other people in other places.

He does not consider the wider implications of his decisions. He does not take responsibility when these decisions go wrong. Instead, he acts on whim and impulse, and when he changes his mind—when he feels new whims and new impulses—he simply lies about whatever he said or did before.  …

Surely, foreign statesmen whispered, he adheres to some ideology, some pattern, some plan. …

This week, something broke. Maybe Trump does not understand the link between the past and the present, but other people do. … He doesn’t seem to remember or care what he said to their leaders last month or last year, nor does he know how his previous decisions shaped public opinion in their countries or harmed their interests. But they remember, they care, and they know. …

If allied leaders thought that their sacrifice might count for something in Washington, they might choose differently. But most of them have stopped trying to find the hidden logic behind Trump’s actions, and they understand that any contribution they make will count for nothing. A few days or weeks later, Trump will not even remember that it happened.