Steve Mariotti left his import/export business to become a New York City teacher. He has taught at some the city's worst schools. At first he says he was a horrible teacher who often lost control of his classes.

One day he asked the kids what was wrong with his teaching style. One kid said, "Well, we did it because we can't stand you. You are boring." He replied, "Well was there ever at time when I was a good teacher, when I touched you or taught you something that had any value?" The same young man said, "The only time you really had value to us, to me, was when you told us about your import/export business. And you'd bring ladies shoes in from Agra, India, add $1 on for insurance and freight, take it down to the Lower East Side and sell them for $7, and your income statement would be $126,000," Mariotti recalled.

The student had remembered that story from the beginning of the term. "Here was a guy that had been defined as - as brain-damaged, emotionally upset. People were afraid of him. And he'd re-created in total a Harvard Business School income statement," Mariotti said.

It is not just about the "greed" (making money), but also about a good story that has real impact. People, no matter what age, must see a learning moment as relevent and important. If that teaching or training moment has no real impact on the learners' lives, then why should they bother to remember it? While it may seem logical for one to learn math, our emotions have more much more impact upon us because they personaly inform us as to what is really important in our lives. And good stories, like Mariotti's, work because they are able to draw the learners in, rather than simple tell them something.

Full 20/20 story, to include a short video, at ABC's site.