A physics lesson and a blueprint for teaching.

Across nearly four decades as a teacher, principal, superintendent, funder, and now leader of a large education nonprofit organization, the experience that most shaped my view of learning wasn’t a grand reform or a shiny new program. It was a Friday physics lab in Brooklyn. My students predicted a graph that couldn’t exist—a vertical line for velocity and time. What followed was confusion, debate, trial, and error. And then discovery: Velocity requires both displacement and time. That brief struggle taught me, the teacher at the time, more about how learning really happens than any policy memo ever has.