Mr. Turkentine (David Battley): "We have here nitric acid, glycerine, and a special mixture of my own. Together it's horrible dangerous stuff, blows you up. But mixed together in the right way, as only I know how, what do you think it makes?"
Charlie Bucket (Peter Ostrum): "I don't know, sir."
Mr. Turkentine: "Of course you don't know. You don't know because only I know. If you knew and I didn't know, then you'd be teaching me instead of me teaching you. And for a student to teach his teacher it's presumptuous and rude. Do I make myself clear? "
Charlie: "Yes, sir."
Mr. Turkentine: "Good."