@passenger
My book would be Shadows of the Mind by Roger Penrose. Same theme, consciousness.
It wasn't what I was expecting. Very math-y.
Now might be a good time to take a peek at it again, actually. It's got more relevance than it did 20 years ago. Also, I've experienced some things since then.
You turned it from "unlikely to be read" to "next on my list" as I answered the question.
Honorable mention: A murder mystery written by a customer, who I was talking to as a cashier. I was so happy to meet a published author, I bought his book from him just to show support. Opened it up, religious themes.