Μεγάλοι δὲ λόγοι μεγάλας πληγὰς τῶν ὑπεραύχων ἀποτίσαντες γήρᾳ τὸ φρονεῖν ἐδίδαξαν → The great words of the arrogant pay the penalty by suffering great blows, and teach one to reason in old age
(see also ἀδυνατέω): be unable
