I used to play teacher as a kid. I had my cabbage patch dolls and stuffed animals all lined up, eager recipients of my brilliant eight-year-old instruction. It was always more difficult to play teacher with real humans. If I convinced my brother or a friend to join in, I didn’t like how it went. I wanted quiet, motionless learners. Wouldn’t that make your job so much easier? Unfortunately, we are not trying to educate...