This has only happened to me a handful of times in my life: dreaming that I was explaining my book in progress to somebody, and discovering upon waking that what I was saying actually makes sense. So much sense, in fact, that the dream conversation gives me some understanding that I'd never reached consciously but that actually helps me write the thing.
The dream I had the other morning may have been the most useful yet. In it I was telling some poor, long-suffering (but mercifully unreal) acquaintance what The Undressing of America is really all about, at its core. What I was saying wasn't, in fact, what it's "really all about," but it was an important piece that I hadn't really looked at yet: how some people, breaking crossing social boundaries and existing in multiple worlds can befriend such a variety of other people that they become sort of living cultural crucibles—and how there are moments (like early 20th century America) when the culture is changing so quickly and the social lines are so blurred that those people can embody an entire historical moment.
I've always been drawn to the combining of different worlds myself: in my public-speaking bio I used to say that I was the only person every published in Batman comics and The Atlantic Monthly in the same month, and sometimes I'd add that I got onto Fresh Air because I wrote Pokemon. And I know that's much of what drew me to the stories in this book: Bernarr Macfadden, the professional wrestler and carnival strongman who knew Upton Sinclair, Margaret Sanger and Benito Mussolini; Fulton Oursler, newspaper reporter, playwright, and stage magician who knew Conan Doyle in his weird dotage and the founders of Alcoholics Anonymous in their early years of sobriety. I know that's much of what draws me to stories about New York in the teens and 20s in general, where the highest tumbled and the lowest rose up and every connection was improbable. But I hadn't really understand that that was a vital part of the book—that those line-blurring, category-jumping relationships were essential to America's psychological and social undressing. Not until my unconscious got to work on it in my sleep.
Anything like that ever happen to you?