Jefferson captures something peculiar about human suffering—that we're often wounded twice, first by imagining disasters that never materialize, then by the lost peace we might have possessed instead. Most people assume the quote warns against needless worry, but the sharper point is about *cost accounting*: we rarely tally what anxiety itself has stolen from us until it's gone. A parent might spend sleepless nights fretting over a teenager's risky behavior, only to look back years later and realize the actual harm came not from what happened, but from the years of dread that turned easy affection into tense vigilance. The cruelty isn't that we worried for nothing—it's that we've spent currency we can never recover.