I attended the live webinar on Calculus for 7 Year Olds (yes - 7 year olds!) hosted by Maria Droujkova and featuring Don Cohen - the Mathman - an 80 year old man who has been working with young people to help them understand the basics of high level mathematics for years.
Don is a very humble, engaging man who reminded me of my college cross country coach, Gene Shirk, who at age 80 in 1981 was the oldest active coach at any level in the NCAA. Coach Shirk would tell our teams story after story of his life experiences - from his trip to the 1936 Summer Olympic Games where he saw Jesse Owens interchange with Adolf Hitler to his time as a two term mayor of the city of Reading, PA - and relate them to cross country running. From a one hour webinar, I suspect that Don's conversational style would yield very similar stories in regards to mathematics.
Don does not refer to himself as a "mathematician", but rather one who "listens to his students" and helps them to learn math concepts by visualization and helping them "learn to learn". His youthful enthusiasm and excitement about his students accomplishments are testament to how he approaches life. He is certainly an inspiration to his students and to those of us who have only met him for one hour in an online webinar!