good-humour
From LSJ
τοῖς πράγμασιν γὰρ οὐχὶ θυμοῦσθαι χρεών· μέλει γὰρ αὐτοῖς οὐδέν· ἀλλ' οὑντυγχάνων τὰ πράγματ' ὀρθῶς ἂν τιθῇ, πράξει καλῶς → It does no good to rage at circumstance; events will take their course with no regard for us. But he who makes the best of those events he lights upon will not fare ill.
