Carry a notebook and write down examples of good and poor design. After a week, you'll begin to realize that nearly everything is the product of a design decision.
I think people get satisfaction from living for a cause that's greater than themselves. They want to leave an imprint. By writing books, I'm trying to do that in a modest way.
I tend to pull nuggets out of many books - rather than having a handful of books that serve as guiding lights.