Not trying to speak for the parent commenter that posted, but those books are part of an overall shift in my career/business thinking from "me working more" to "building assets/systems that work for me".

I'd throw in Ramit Sethi's writing as well in shifting me from trying to "cut" as much expense but rather to grow the profit side of my work.

in my case - it changed how i think about "buying things" and how to priorities spendings that will yield return over just immediate pleasure.