This cartoon of his is a favorite of mine, those three words speak so much to me. They describe so much.
He wrote a fantastic article on creativity (I looked it up just now to link you to it, to find it’s over 10 years old. It’s stuck with me all that while!)
If you’re a creative (in any field) with a creativity block – artistically constipated – this is a great resource of timeless advice, and a place to go and cogitate on the nature of making.