I wish I'd self-published sooner
30+ years ago, Doubleday published my book.  It would not have happened if it weren't handled by a literary agent (John Brockman). The original title of my book was "Fundamentals of Computer Security in a Networked Environment."
  ch 1) Hardware (registers, memory, disks, etc)
  2) Software/OS (Unix, etc)
  3) Application S/W 
  4) Networks - TCP, IP, Arpanet
  5) Security - encryption, trapdoor functions, etc
  and so on.  20 or 30 chapters.When I sent the book proposal to Brockman, he told me bluntly: "I can't sell this.  You can't write".  Three months later, the story found its way to the front page of the NY Times.  First person who called (at 3AM Pacific time): John Brockman.  "Lemme sell your book!"So he went ahead and sold the book proposal.  Didn't just sell it.  He auctioned it amongst publishers.  End of the day, there was a $40,000 advance (wow - more than I was making on my job!)I started writing: got through the first 5 chapters.  Then my friend, Guy Consolmagno visited (he was joining the Jesuits).  I showed him the manuscript, and as he read it, his face dropped.  After 30 or 40 pages, he looked up and said, "Cliff, this is terrible.  It's all about computers.""Of course, I replied,"I'm writing a book about computer security,"Guy answered: "Every computer jock in the world will want a copy.  Doubleday will probably sell 600 copies.""Yep, that's the book proposal that they bought!""You idiot! They don't want to sell 600 copies," Guy said. "They want to sell 6 thousand.  Maybe 60,000.  You gotta do better than this...""Look, Cliff. Don't write about computers," Guy continued. "Write about people!""It's not about people," I replied.  "The book's about the Arpanet, about crypto systems, about os holes, about how to manage a Unix system.""No it ain't," he said.  "It's about those hackers in Germany.  The bureaucrats in the FBI who have never touched a computer.  The NSA people who listen but won't lift a finger.  The CIA agents who pester you in Berkeley.  It's about the long-hair computer jocks you work with.  It's about the nutty living situation you're in.  Most of all, it's about you."Well, I listened to my friend. Tossed those chapters and rewrote 'em. Told my story in first person.Today, many of you now know me because of that book.Editing? Mainly my sister Jeannie (who's a professional editor) and David Gernert of Doubleday.Brockman? He's still running a literary agency in New York.  Brother Guy?  He's now the director of the Vatican Observatory.  Me? I'm still in the Bay Area, wondering how I ever wrote a book.