“In the beginner’s mind there are many possibilities, but in the expert’s there are few.”
-Shunryu Suzuki
Suzuki was a Zen master.  The quotation is from his book Zen Mind, Beginner’s Mind.
It occurs to me the more expert we become and the more we crystallize our style the more imperative it becomes to nurture the beginner’s mind, to maintain an awareness of the many possibilities available to us.  To not be so aware could lead to an expertly dug dogmatic rut.