The document tells a story about a boy who has a difficult temper. His father gives him nails and tells him to hammer one into the fence every time he loses his patience. The first day he hammers 37 nails. Over time, as he learns to control himself, fewer nails are hammered each day. Eventually he is able to remove all the nails, having learned self-control. However, his father notes that while the nails are gone, the holes they left in the fence remain, just as hurtful words can leave wounds even if apologies are given. The document encourages being a good friend and treating others with respect.