A boy is given a bag of nails by his father and told to hammer one into the fence each time he loses his temper. Over time, as the boy learns to control himself, fewer nails are hammered into the fence. Eventually, the boy is able to remove all the nails, but his father notes that the fence will never be the same due to the holes left behind, just as hurtful words leave wounds that don't fully heal. The document encourages treating friends and others with kindness, love, and respect.