Shirley and Earl McNall knew they had one hot little entrepreneur on their hands. Son Bruce was only five, and he could wipe everybody out at the Monopoly board, building hotels on all the expensive properties, leaving his mom stewing with an empty lot, say, on low-rent Baltic Avenue. Dazzled, the mother, a lab technician, and the father, a biochemistry professor at the University of Southern California, rationed Bruce's television watching and showered him with intellectual goodies.
The pampering paid off. Bruce became a wealthy coin collector while still in his teens. Then he collected a hockey team, collected a football...