This book grows out of an attempt to understand the greater sense of agency and competence I have always felt doing manual work, compared to other jobs that were officially recognized as "knowledge work." Perhaps most surprisingly, I often find manual work more engaging intellectually. This book is an attempt to understand why this should be so.
That's from Matthew B. Crawford, who has a Ph.d. in political philosophy from the University of Chicago yet now runs a motorcycle repair shop in Richmond. I would cite shooting baskets, walking, and cooking as three of my analogous "intellectual" activities.