Trevor Bauer is a Major League Cy Young award winner. Despite whatever shortcomings he has off the field, he has changed the on-field baseball world for the better with his cutting edge training methods and ideas. He has an analogy about learning that shines a light on the journey it takes to master something. He equates learning something new to passing through the middle of an Oreo cookie. The first brown cookie is simplicity, the white filling is complexity, and the second brown cookie is simplicity regained.
When you first begin to learn something new that you eventually want to master, you experience this simplicity in the carefree way you make mistakes, expecting nothing of yourself, really just enjoying it and having fun.
Soon you begin to enter into the white-filling of complexity. This phase lasts for years and is where you learn all of the lessons worth learning. Few are able to make it out of this phase, and you are tested and tried over and over again.
Finally, if you are willing to stick with it long enough, you may enter the second brown cookie of simplicity.
D.T. Suzuki in the introduction to Zen in the Art of Archery sums it up like this:
Man is a thinking reed, but his great works are done when he is not calculating and thinking. “Childlikeness” has to be restored with long years of training in the art of self-forgetfulness.
Daisetz T. Suzuki
Finally, what we call the “self-forgetfulness” or “letting-go” that happens in the second cookie of simplicity is more commonly referred to as wisdom in our lifes’ everyday walk. Read carefully how Orthodox theologian David Bentley Hart sums it up:
Wisdom is the recovery of innocence at the far side of experience; it is the ability to see again what most of us have forgotten how to see, but now fortified by the ability to translate some of that vision into words, however inadequate.
David Bentley Hart
P.S. A couple resources that can help you understand or better visualize how this works are the IQ Bell Curve/Midwit meme and “Four Stages of Competence.”
Braden Bristo’s - The Journeyman’s Path 