I agree with you both. I like to think I'm a good teacher, and if they don't understand then it's down to me not them.

But I was given an 'apprentice' to teach. He was very willing to learn, very interested in the subject (programming) but only insofar as I poured the knowledge into his ears. He would not do any work I set him so pretty soon I threw in the towel. I really enjoyed teach, he really enjoyed learning, but his dismotivation finished it, what a waste.