A man who fears suffering is already suffering from what he fears.

Fear of pain is itself a kind of pain, and often it arrives long before the thing we dread, if that thing ever arrives. The mind has no good way to tell a vividly imagined hardship from a real one, so it pays the price in advance: the tight chest, the sleepless night, the rehearsed disaster. By the time the feared event comes, we have already suffered it once, and sometimes it never comes at all.

This fits Montaigne's temperament. He drew on the Stoics, especially Seneca, who noted that we suffer more in imagination than in reality, and he turned that lesson on himself, a man who admitted to being fearful by nature. The exact wording circulates in several versions, so it may be a loose paraphrase of his thought rather than a verbatim line, but the idea is clearly his.

Suppose you have a medical test and the results take a week. You can spend that week living through every bad outcome, or you can do what is actually in your hands, such as booking the follow-up and asking your questions, and then return to ordinary life. The worry may not vanish, but you stop paying for something that hasn't happened.