If only they knew...

Curious to know if other authors have amusing little secrets about their books (maybe not quite "secrets" but trivia, I guess) that would surprise reviewers or readers. There's one thing that keeps coming up for me...

A few times now, in various milieux, people have told me that my third book is stronger, better, more something something something than books 1 and 2. They comment on how I've grown or developed or something something something as a writer.

I take the compliment and feel all warm and fuzzy inside, BUT BUT BUT my 3rd book was actually written first, or at least about 85% of it was. I couldn't figure out how to end it, so I shelved it and wrote book 1. Then I tried again with the abandoned book and still hit a wall, so I wrote book 2. Eventually, I figured out what to do with the ending and so book 1 was finally published as book 3. The parts written way back when (2005) are unchanged in the now published form.

What about other authors who have a funny little back story about their own works? I'd love to hear some of your anecdotes.