Proverbs 22:6

Train up a child in the way he should go: and when he is old, he will not depart from it.

The usual interpretation of this proverb is that if parents train up a child properly, they will go on in that direction later in life. But this verse can serve as a warning to parents that if they allow a child to train themselves after their own wishes, they should not expect them to change those patterns when they mature.