"I spend quite a bit of time thinking about my students. I look at them, at their work, I listen to what they tell me, and try to figure out who they might become in the best of all possible worlds. This is not easy. Students try to give you clues; sometimes they look at you as if imploring you to understand something about them that they don't yet have the means to articulate. How can one succeed at this? And how can one do it 20 times over for all the students in a class? It's impossible, of course. I know this, but I try anyway. It's tiring."