I liked what his nephew had to say about him:
SIEGEL: All right, he would say, I am an actor, not a clown. Obviously, that distinction is important to you today and it was to him. Why?
WALKER-PEARLMAN: Because he came to humor from a very emotional place. His mother was very ill when he was 9 or 10 years old. That was my grandmother. And the doctor said, don't make her angry 'cause if you do, you could kill her. But you can make her laugh. So he found a way to make her laugh, but it was all based on emotion.
And then he fell in love with acting.
http://www.npr.org/2016/08/29/491856...in-willy-wonka