Shunryu Suzuki:

Naturalness is always there, moment after moment. But usually, forgetting all about naturalness, you behave as if you have something. What you do is based on some possessive idea or some concrete idea, and that is not natural. For instance, when you listen to a lecture, you should not have any idea of yourself. You should not have your own idea when you listen to someone. Forget what you have in mind and just listen to what he says. To have nothing in your mind is naturalness. Then you will understand what he says. But if you have some idea to compare with what he says, you will not hear everything; your understanding will be one-sided; that is not naturalness. When you do something, you should be completely involved in it. You should devote yourself to it completely. So if there is not true openness, it is not natural.