My son's homework said, 'A truck carries 50 boxes. Each box weighs 12 pounds. How many trips does the truck need?' I said, 'That's 600 pounds.' He said, 'No, Dad, the question is how many boxes fit in the truck.' I said, 'The truck is a metaphor, son.' He said, 'The truck is in the picture. It has a cab. It has wheels. It is not a metaphor.'