“Strike a scoffer, and the simple will become wary; rebuke one who has understanding, and he will discern knowledge…Cease listening to instruction, my son, and you will stray from the words of knowledge…Listen to counsel and receive instruction that you may be wise in your latter days” (Proverbs 19:25, 27, 20).
Some people have a lifetime enrollment in the School of Hard Knocks. The only way they might learn from a mistake is by doing it themselves. This is one way to become wiser, but the tuition cost is quite high.
A simple person (someone who understands his need to gain wisdom) can learn from the mistakes and folly of others. When a scoffer, for example, gets bitter consequences for his foolish decisions, the simple person takes note and increases in wisdom. This is one of the cheapest ways to gain wisdom.
For a person pursuing wisdom, a simple rebuke is enough to drive the folly from his heart and mind. He is not so hardheaded and foolish that he will need physical pain to become wiser.
To be wise you must listen to counsel and receive instruction directly and by learning wisdom from the mistakes of others. When you cease listening to instruction and learning wisdom from others, you have taken the first and biggest step in the direction of folly.