Soon, the farmer hears noises coming from the barn and goes to investigate. He then sees the salesman coming out of the barn-soaking wet and with a white liquid dripping down his face. The farmer asks, "What happened to you?" The salesman says, "I just got thirsty, so I milked your cow. It was so dark in there I don't know how I did it. But I'm telling you, that cow has great milk! I must have drank a gallon of it!"

The farmer then stares at him with a puzzled look and says, "But we don't have a cow. We just have a bull."