Bede

It is a proverb, Train up a child in the way he should go, etc. It is evident that many change from the vices they had as youths in old age, by the gift of the Lord, and conversely, some, by the Lord deserting them, abandon the virtues they seemed to have displayed in their youth. But because much more often each one is accustomed to follow the habits with which he was imbued from youth into the remaining time of his life, he says there is a proverb, because what anyone takes up in youth, he will not change in old age. …

Commentary on Proverbs ↗