I am an optimist, unrepentant and militant. After all, in order not to be a fool an optimist must know how sad a place the world can be. It is only the pessimist who finds this out anew every day.

Ustinov frames optimism not as naïveté but as a hard-won stance that fully acknowledges suffering. The “unrepentant and militant” optimist is someone who chooses hope and constructive engagement despite knowing how bleak the world can be. By contrast, the pessimist is portrayed as repeatedly “discovering” the world’s sadness—experiencing disillusionment as a daily shock—because pessimism offers no stable, purposeful response to hardship. The epigram defends optimism as intellectually honest (it requires clear-eyed knowledge of tragedy) and ethically active (it implies resolve to act), while casting pessimism as emotionally repetitive and ultimately unproductive.