A teacher's success is as much dependent on his teaching prowess as it's on the dialogue across the table, between him and the students. A teacher should be able to guide the student through the crests of knowledge and wisdom and the troughs of desperation, through the illuminating highways and through the dark alleys, but for a teacher to be able to do so, s/he should know where exactly the student stands. Not just that, sometimes it's very important to just give a clue and then allow the student to grope in the uncertainties, to finally emerge triumphant. There are two reasons for this. First, independence, which will lead to a habit of finding one's own answers whatever may come. And second, something completely unimaginable getting unravelled in the process...