I can see that being good practical advice for getting things done, but I'm less sure it's good (or at least universal) life advice, especially to follow all the time. My model for a good day spent is a lot of intermingled puttering around, reading, thinking, relaxing, working, to make unexpected connections between things, find new angles on problems, and generally understand how everything fits together better. Like the way a Douglas Hofstadter book "flows". I really, really dislike the "work-hard / play-hard" lifestyle; just doesn't work for me at all.