We are all artists, painting our lives upon the canvas of reality. Mix the colors your own way and apply emotion liberally. Don't be afraid to let your brushstrokes show, and about all else, make sure your art has soul.
If you think about it, everyone IS mad. They are mad because they've let life and reality to get in the way of themselves... so Cheshire's is essentially right because the ONLY thing we need to combat reality is imagination and vice versa.