A large sign in front of a shop—“No change is given.” One day, a customer asked the shopkeeper out of curiosity, “Brother, why is it written so strictly?” The shopkeeper smiled and said, “Brother, I used to give change first. Then when I asked for money, there would be arguments, quarrels, and anger with the customer—everything. Some would say I will give it tomorrow, some would say the day after tomorrow. In the end, the relationship would be ruined.” The customer said, “So this sign is to avoid quarrels?” The shopkeeper nodded and said, “Yes, if you tell me in advance, it will reduce the trouble. Business also runs smoothly, and relationships also remain good.” The customer smiled and said, “But your intelligence is not bad!”