The Scene. It arrives uninvited, usually late — the decision you didn't make, the job you turned down, the words you should have said to someone who is no longer around to hear them. You lie in the dark and run the tape again, editing a past that has already been printed. Nothing changes. You just lose the sleep.
The Voice. Marcus Aurelius, emperor of Rome and the most reluctant of philosophers, kept a private notebook we now call the Meditations — never meant for us, which is exactly why we trust it. He carried the weight of an empire and its wars, and had every reason to brood on what he might have done differently. Instead he gave himself a sharper instruction. In George Long's public-domain translation, he wrote: "Confine thyself to the present." And he reasoned his way there honestly, noting that "every man lives only this present time, which is an indivisible point, and that all the rest of his life is either past or is uncertain."
The insight is quietly ruthless. The past cannot be reached to be fixed; it can only be reached to be suffered. Regret feels like responsibility — like penance for a mistake — but it is not action. It is the mind paying interest on a debt it can never clear. Marcus understood that grief for a squandered yesterday only squanders a second day on top of it. He did not tell himself to forget. He told himself to return — to the one indivisible point where a person can still actually do something.
The Landing. So take the regret and ask it a single working question: Is there anything here I can still act on? If there is — a call to make, an apology to send, a habit to change — then the regret has done its one useful job, and you convert it into a move today. If there is genuinely nothing left to do, then the ruminating is not paying a debt; it is inventing one. Let the lesson stay and let the sentence go. You are not the person who made that choice. You are the person who learned from it, standing in the only place your hands still work.
The past is closed for repairs. But the present is open, and it's the only workshop you've ever had.