Many authors think about writing a book for over a year before they actually start writing.

Speaking can elicit the same amount of time spent wondering if it's time to actually put together a speech or start charging a fee or making slides to go with those stories you like to tell.

What are you waiting for? Perfect alignment of all forces.  A sugar daddy. A full moon. Just start writing. Start talking. Start putting yourself out there.

Now don't be a total slob and fling stuff out and be a total hack.  But start. I love rough drafts and scribbled notes.  It's the messy, inspired part of the process.

Writing a book can be overwhelming because we make so many rules to follow without realizing it. It can be easy if you let it.  Just start. And then ask for help and expertise. That's why there are editors and rounds of revisions.