The teacher of Torah must not only say things that are correct but also attune himself to his listener.
Otherwise, he has not fulfilled his task.
He needs to know the listener’s preconceptions and the flaws in his thought process so that the listener should find the words acceptable and understandable within the context of his own mind set, opinions, and current state of mind and soul.
Thus, it is immeasurably more difficult to speak to two people than to one.
To speak to a crowd–and certainly to write a book–one needs to be, in this sense, a “leader for Israel” who can speak simultaneously in all languages, so everyone can relate to his teachings.
–Rabbi Adin Steinsaltz