Wow, that title! Productivity is something I've been trying to pin down (given all the literature, as you said, on hacks, systems, etc.). I recently wrote about productivity being only a part of overall fulfillment, and the other part is doing things that are simply "existing." Like Yin and Yang, they depend on eachother. Maybe "existing" (a.k.a taking a walk) leads to the self-discovery you've written about here, which fosters that productivity :) Thanks for the great read!