Throughout this book King shows why he’s such a great author. He is irreverent. He lacks reverence for people, places, things, and ideas just because others want him to revere them. If he reveres something it must go through the gauntlet of his scrutiny.
King starts this book as autobiography then ends it by making suggestions to writers about their craft. It is similar to Richard Williams in BLACK AND WHITE who starts off with autobiography then ends with his thoughts on parenting. In both books the autobiographical narrative opens the reader up to hear the admonitions about writing for King and about parenting for Williams.
Ultimately, King teaches writers (and teachers) to practice irreverence. Irreverence is precious for the cause of freedom. To maintain freedom and a sense of self, irreverently confront status quo. Bash status quo then construct your own ideas when necessary and embrace it if it makes it out on the other side of the gauntlet.