Teaching piano poses real dilemmas; among them, whether it is more important to be interested in what the student plays or to demand that the student's playing make no particular demands on the teacher's comprehension.
Opting for the first alternative, I find the students develop their musical minds in individual ways, only some of which make "sense" to me. That they interest me, even though I do not understand them, is proof enough to me that they are up to something.
The alternative is to require that all children sound more or less the same, or at least make the music sound more or less the way it has already sounded in someone else's hands.
Again and again I am reminded of how bored I was as a youngster playing what I now recognize to be the great masterworks of the piano. I will not allow children to begin a lesson by saying they have not practiced. And I will not allow them to be bored with masterworks. It is a challenge to figure out how to keep boredom from becoming an option.