Quick answer
Honor runs both directions between generations. Grandparents wear their grandchildren; children are lifted by a father worth having.
Read both lines
The reciprocity is the substance. It would be easy to write a verse about what the old owe the young or the young owe the old, and this one instead describes each generation as the other's adornment. "Crown" is a public word, so the claim is that a long life's real display is who came after. The second line assumes something the book cannot guarantee and knows it, since Proverbs is realistic elsewhere about fathers who bring shame. Read as a description of how a family can work, it is warm; read as a promise, it would wound anyone whose father was not that.
Related: Proverbs 13:22 · Proverbs 17:21 · Proverbs 20:7
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.