The father here in these verses of Proverbs is imparting perspective to the generations that follow him. In particular, he is continuing his teaching on the dangers of adultery and forbidden sexual relationships. He is telling his sons (all of his posterity) to listen to the perspective of an older man. They will lose so much life if they look for sexual fulfillment outside of marriage. Whatever pleasure they think they might gain will ultimately end in regret.
Very few people will ever receive a crown of a kingdom in this life. In truth, I'd say there's basically no chance that you or I will. (I'm just guessing there are no kings or queens reading this!) Yet, there is a way for you to receive a crown, and it's a crown that lasts eternally. Eventually, King Charles' crown will no longer be on his head, and he will stand before God as a man, just like you and me. His only hope as he stands before the throne of God will be the righteousness of Jesus.