What was amazing is that Vishwanath was different in the sense that he taught, a subject like mathematics, without using a pen/paper or board/chalk; making us develop listening, comprehending, in a sense visualised memorying. I have never heard anybody doing that. His approach was that I have to do things by myself and steadily gain more and more confidence. He taught once means I learned it very well and almost not needed to re-learn - the topic would be incorporated in me in one go, applicable to all ideas, theory and problems; not just what was in the text book but an in-depth understanding of related topics also. Teaching method is perfect. Makes everybody understand. He is passionate.