It started when I was about 14. In Illinois, that's when you can start working (with your parents' permission). So I went with my dad to get a worker's permit and got a summer job at the local grocery store. I don't remember learning much there. But a year later, at my next summer job, the lessons flowed.

I was working at Shelby's Pro Shop, a golf and tennis retailer in Deerfield, where I grew up. I sold shoes and tennis rackets. I didn't play tennis, but I learned how to be a very good tennis-shoe and tennis-racket salesman. That's because I made the discovery that people's reasons for buying things often don't match up with the company's reason for selling them.