This reminds me of the movie/book 'The Peaceful Warrior' by Dan Miller (... <i>there's never _nothing_ going on!</i>)<p>There are two distinct 'incubation' type behaviors that I have observed - one is the internal thinking that you describe in this essay (showers, running, walks, yoga, or just sitting on the edge of a cliff and looking at the world).<p>The second type of incubation behavior is a type of 'prattling on'. Doodling, drawing mind maps, morning pages, stream of consciousness, etc.<p>Mind you - mind maps can be used very constructively, but sometimes it's just a type of brain dump.<p>I find that the second type of processing is useful when my mind is so full that I get stuck in an idle loop: nothing useful coming out at all; a cross between analysis paralysis and broken record.