Writer Donald Barthelme in his essay "Not-Knowing" says the writer not knowing what he or she is on about when he or she starts writing is crucial to the process. The process of writing is built around honed intuition, and for the writer, it all might as well be magic.
In this same essay on craft, Barthelme worries about many other things besides. One is the shrinking audience for literature. Another is the competition with TV and film. And still another is the possibility that the contemporary writer might have finally arrived at the point where there is not much more to do by way of art. Most of Barthelme's essay focuses on this latter issue.