Act well thy part! Marcus Aurelius 3.8

Marcus advises himself to act always with purpose. See your role in life's drama and play it deliberately, or fate will find you weak, unprincipled, and reactive—thrashing about as you suffer pointless pain from a past you don't understand.

Οὐδὲν ἂν ἐν τῇ διανοίᾳ τοῦ κεκολασμένου καὶ ἐκκεκαθαρμένου πυῶδες οὐδὲ μὴν μεμολυσμένον οὐδὲ ὕπουλον εὕροις· οὐδὲ ἀσυντελῆ τὸν βίον αὐτοῦ ἡ πεπρωμένη καταλαμβάνει, ὡς ἄν τις εἴποι τὸν τραγῳδὸν πρὸ τοῦ τελέσαι καὶ διαδραματίσαι ἀπαλλάσσεσθαι· ἔτι δὲ οὐδὲν δοῦλον οὐδὲ κομψὸν οὐδὲ προσδεδεμένον οὐδὲ ἀπεσχισμένον οὐδὲ ὑπεύθυνον οὐδὲ ἐμφωλεῦον.

You'll find no pus oozing in the mind of one chastened and cleansed, nor any old wound rotting or festering. Fate never seizes this man unaware, acting without purpose, so that an observer might say he departed the tragic stage of life without filling and finishing his role. His mind has nothing servile or frail, no self-attachment or separation, no guilt and no guile.