The expression on his face when she says nice is nothing short of stunned. It's only present for a moment before he forces himself to look away to coach a look of reproach onto his face again.

"No, I was not 'some kind of professor'." His sharp tone of voice is pure compensation for his previous agreeability. "I have lived with magic for a very long time, just as I have lived without it. Explaining its concepts so that others have a modicum of understanding ensures that they do not make some foolish mistake out of ignorance." Not that he enjoys doing so. Surely.