Standing directly in front of me, you raised your right leg and your left arm. I thought I did just the same, until you asked me, how many feet I had, and whether, I was trying to be original!

I had relied only on my vision of you and not listened to what you said. That would have been sufficient, if only you had turned around, and done all that, with your back to me.
But then, you wouldn’t have known, upon which leg I stood.

Perhaps there are times, when a teacher has to say nothing, turn his back, do what he has to do, and trust the student will follow.