Adding to an already rich life, my father decided in middle age to become an elementary-school teacher in a working-class neighborhood in New Mexico. To this day, people who run grocery stores and work on construction sites, and who are now in late middle age themselves, come out when I’m visiting to tell me how Mr. Lanier changed their lives. Go up to any adult with a good life, no matter what his or her station, and ask if a teacher made a difference, and you’ll always see a face light up. The human element, a magical connection, is at the heart of successful education, and you can’t bottle it.