The purpose of the proverbs is education -- for attaining wisdom and discipline, for understanding words of insight. My grandmother used to say "experience is a dear school, but a fool will learn in no other."
Proverbs are short truths drawn from long experience. When we learn from other people's experience, we take ourselves out of the category of "fool" and put ourselves into the category of disciple.
Fool here doesn't mean just silly or someone to laugh at. Fool in this context means perverse as well. Perverse: stubborn, hardheaded.
At one point, the Lord calls the children of Israel "a stiffnecked people." Stiffnecked: proud, stubborn, perverse. it wasn't a compliment.
A teachable, humble spirit is the mark of a true follower of Christ. While we know what we know, we are always ready to learn more of the Lord.
Keep us from pride and stubbornness. Help us to be hungry to know more of You. Grant us a teachable spirit.
In Jesus' most precious name.