There is a sacred entrustment in art of any kind. Craft will take you half the way there--learning your instrument, honing your skill. But art exists somewhere beyond craft, when something is produced through you, not by you. The greatest artists are the most humble, because they are the most subservient to their muse.
Writing a memoir and writing a novel have been, for me, two very different enterprises. In one, I was creating a story from the details at hand. In the other, I was making things up to move the plot and the characters along. But in both, as the author, I was committed to the same high calling: telling the truth.
Truth-telling is tricky in a memoir. You might remain faithful to the details of the events you describe, but you are also trying to tell a particular story about your life. From the distant vantage point of the entire narrative arc, you get to choose which details you include, and which you leave out. When I was done, being prudent, I shared my manuscript with several ex-es. Each pointed out how they saw things a little differently. But of course they did!
In a novel, truth-telling is more subtle. All the way along, you're making stuff up. But there is still a certain inner truth you must recognize, and obey. Characters come fully formed--at least they do for me. They already know who they are and will tell you in no uncertain terms when you, the author, have them doing something they would never do in a lifetime, or saying something they would never say. Similarly, the story line has its own path and will be neither rushed along nor side-tracked, without making you pay.
In sacred poetry, from 13th Century Sufi mystic Rumi to modern-day songster Leonard Cohen, the poet often addresses an unnamed Other who makes demands and who imparts judgement, or grace. "Show me the place, where you want your slave to go," Cohen sings. My own muse is like that. I don't call upon my muse to help me or to inspire me. Rather, I do its bidding and ask only that I not fail in that task. I am the servant in this relationship, not the master.
Perhaps this makes the writing process sound more mystical than it really is. After all, I'm the one committing words to the page, and then attaching my name to them at the end. But, whether in memoir or in fiction, I'm not the one writing the story. The story is writing me. I work at the words with the highest skill I can summon, until it satisfies the inner voice that whispers in my ear: "Closer ... closer ... closer."