Grandpa was a gentle but firm primary school principal in Pretoria, South Africa. In my final year as a student teacher, he shared a few trade secrets with me. His advice on how to get a disruptive pupil out of the classroom and into isolation was most helpful: “Look the child in the eye and say with authority, ‘Follow me,’ then turn and walk confidently out of the classroom while not looking back.” I tested his advice when dealing with an unruly adolescent and, though I doubted it would work, I soon heard him reluctantly following me.