“It is not the thing itself that disturbs man, but his judgment about the thing.”Marcus Aurelius · Gânduri către sine · 180 · Cartea VIII, 47
The event is silent; the pain is the sentence you add, and you can rewrite it.
Between a fact and your pain stands a sentence you compose yourself: "this is a catastrophe," "this humiliated me." The bare fact is mute. A traffic jam can be lost time or time for a podcast, depending on the judgment. Marcus Aurelius does not deny reality; he shows that suffering has a component you draft yourself, and can therefore rewrite.
Why it matters It is the core tool of any rational therapy, usable at the day's first frustration.