Thou shalt learn,
Late though it be, the lesson to be wise. (tr. E. H. Plumptre)
γνώσῃ διδαχθεὶς ὀψὲ γοῦν τὸ σωφρονεῖν.
Original text (Ancient Greek)
Notes from Wikiquote
Old as you are, you shall be taught some wisdom yet. (tr. P. Vellacott)