וְלֹֽא־נָתַן֩ יְהוָ֨ה לָכֶ֥ם לֵב֙ לָדַ֔עַת וְעֵינַ֥יִם לִרְא֖וֹת וְאָזְנַ֣יִם לִשְׁמֹ֑עַ עַ֖ד הַיּ֥וֹם הַזֶּֽה׃
but the LORD hath not given you a heart to know, and eyes to see, and ears to hear, unto this day.
Pirkei Avot
He used to say: At five years of age the study of Scripture; At ten the study of Mishnah; At thirteen subject to the commandments; At fifteen the study of Talmud; At eighteen the bridal canopy; At twenty for pursuit [of livelihood]; At thirty the peak of strength; At forty wisdom; At fifty able to give counsel; At sixty old age; At seventy fullness of years; At eighty the age of “strength”; At ninety a bent body; At one hundred, as good as dead and gone completely out of the world.