Since it is possible that thou mayest depart from life this very moment, regulate every act and thought accordingly. But to go away from among men, if there are gods, is not a thing to be afraid of, for the gods will not involve thee in evil; but if indeed they do not exist, or if they have no concern about human affairs, what is it to me to live in a universe devoid of gods or devoid of providence? […]
Memento mori is not a goth aesthetic. It is a daily reordering: if this is the last day, what do I refuse to spend it on? The Stoic answer is consistent — pettiness, anger over things outside your control, the chase for praise. The corollary is that the things worth doing today are the same things worth doing if you had a year.
Marcus Aurelius, Meditations 2.11 · trans. George Long (1862)
Context
Marcus Aurelius writes the Meditations not for publication but as a working journal. This passage is one of many where he reminds himself, quite literally, that the next breath is not promised. The function is not morbid but ordering — daily confrontation with finitude clarifies what matters.