Our everyday life is like a movie playing on the wide screen. Most people are interested in the picture on the screen without realizing there is a screen. When the movie stops and you don't see anything anymore, you think, "I must come again tomorrow evening. I will come back and see another show." When you are just interested in the movie on the screen and it ends, then you expect another show tomorrow, or maybe you are discouraged because there is nothing good on right now. You don't realize the screen is always there.
But when you are practicing, you realize that your mind is like a screen. If the screen is colorful—colorful enough to attract people—then it will not serve its purpose. So to have a screen which is not colorful—to have a pure, plain white screen—is the most important point. But most people are not interested in the pure white screen.
I think it is good to be excited by seeing a movie. To some extent you can enjoy the movie because you know that it is a movie. Even though you have no idea of the screen, still your interest is based on an understanding that this is a movie with a screen and there is a projector or something artificial. So you can enjoy it. That is how we enjoy our life. If you have no idea of the screen or the projector, perhaps you cannot see it as a movie.
Zazen practice is necessary to know the kind of screen you have and to enjoy our life as you enjoy movies in the theater. You are not afraid of the screen. You do not have any particular feeling for the screen, which is just a white screen. So you are not afraid of your life at all. You enjoy something you are afraid of. You enjoy something that makes you angry or that makes you cry, and you enjoy the crying and the anger too.
The white screen is not something that you can actually attain; it is something you always have. The reason you don't feel you have it is because your mind is too busy to realize it. Once in a while you should stop all your activities and [notice your] screen. That is zazen. That is the foundation of our everyday life and our meditation practice.
See also: A Shining Screen