simplicity is behind all genius. (childlike wonder).
i find that with teaching, as well. you watch advanced teachers and everything comes down to just a few words to express what others might take much longer to say. this must be the half the secret to high powered piano lessons. you sort of zoom right in on the energy level, the few bars of music, and the moment.
seems that mozart knew how to be int eh moment.
also, mozart to me seems to read people like shakespeare. he has this classic sense of characters. you have the stock characters, from times gone by - but he refines and refreshes them to unforgettable dimensions.