I've been reading a lot of books and white papers lately, some related to the industry of the current product I'm working on. Some are further afield.
There's always a good set of books about how to improve our product manager jobs that's coming out. I suspect this will not stop but is another category in non-fiction or career oriented books.
The one that I recently picked up is called, The Messy Middle: Finding your way through the hardest and most crucial part of any bold venture.
Its author, Scott Belsky is the Founder of Behance which was sold to Adobe. He was a acquihire and became Adobe's Chief Product Officer. So he knows a thing or two about product management.
He wrote something that I think is very profound and deserved remarking on. It's not novel an insight, but it is concise in how he characterizes the Messy Middle, which he describes as the journey of the person and product between the initial idea and convention form of success (however you attribute that).
"It is not the plastic, metal, or pixels that makes a successful product or service. Rather, it is the thoughtfulness and though choices made by the makers--the team dynamic, the perseverance, the organizational design (and redesigns), the constraints, the battles fought and the values that govern the path taken."
I think it says it all right there.