If you were about to run a marathon, would you get up on the day of the big event and start running without preparation?  If you did, you'd probably pass out after a few miles of jogging. In order to win, athletes condition and practice. Musicians must rehearse to create melody instead of noise.

Writers are no different.                                       

In fact, writers never stop learning.  As an author, if you ever feel you have come to a point of all-knowing creative expression, you should put down your pen and walk away. It is at that point when your success has ended. I have read books from best-selling authors only to find their next attempt at authorship a complete failure.  The reason for their creative demise was complete satisfaction in their abilities. These authors believed that they had reached the Mt Kilimanjaro of creative expression. They had nothing else to learn.

Don't fall into the trap of the all-knowing writer because in the world of story there is always more to learn.  The beauty of writing for the author is the reality of never reaching the mountaintop.  You always have room to improve, even after you have been a bestseller.