The essence of teaching, the soul of the art, is being brave enough, psychologically unencumbered enough, to see exactly what is taking place in the minds of your students at any given moment and then--like a good psychotherapist--speak to and through their defenses to uncover the true promise of the lesson, its hidden meaning. This significance will almost always be different from what you originally took it to be and at odds with the lesson plan. But that is what makes teaching a creative act. One doesn't just dispense information--one brings insight into being. I am surprised by what I teach all the time.