In chapter three of Johnson's book, he talks about the "Slow Hunch." I don't want to spoil his story about the FBI, so I'll just say go read it. But he dashes the notion of the "Ah ha!" moment. Sure it might feel like that when all the pieces fit together, but what goes untold is the development and collection of all those pieces. By studying Darwin's journals Johnson was able to determine that Darwin had all the relevant pieces of the Theory of Evolution, quite a while before he had the "Ah ha" moment. That means even though he had all the facts it still took some time to put them all together in the right combination to bring forth the full idea.
The notion that each time we gather a relevant piece of information it guides us to other relevant pieces of data, he calls the "Slow Hunch." This process might not and probably does not happen in a logical sequential order. Like following the trail of sources in an author's end notes, one might read all those same books and come to a different conclusion or even never draw them all together in a conclusion at all. When telling the story of how an idea came to them, people tend to focus on the dramatic moment of fruiting and not the years of growth from sapling to tree. Newton did a lot of math before that apple fell on his head. But for a visual representation of the idea and a dramatic point in the story that apple to the head really sums it up.
It is also in chapter three that Johnson illuminates the idea of the "Common Place Book." Like a staff officers green notebook or bullet journal (Federal Supply Service 7530-00-222-3521), it keeps all the relevant information in a common place for easy reference. The idea being, that one copies the relevant stuff from the last journal into the new journal, dumping all the dumb and extraneous stuff. At some point the journal is full of only relevant and good stuff. So the process begins again with a new journal. This way the journals that are saved are full of relevant items and worth keeping. It is important to recognize that even in this example of a way to capture the slow hunch, came about as a slow hunch, becoming molded over time until John Locke popularized it and and enterprising publisher, John Bell, brought to market "Bell's Common-Place Book" to which he added the subtitle "Formed generally on the Principles Recommended and Practiced by Mr. Locke" it included eight pages of instructions on how to index and catalog things for easy reference.
If anyone can come by a copy of those original instructions, please contact me!
Johnson goes on with some interesting ideas relating to modern word processing, search engines, data bases, and artificial intelligence. All of which I recommend you read on your own. What strikes me as interesting is that as a writer Johnson has walked the reader through the adjacent possible, liquid networks, and slow hunches and his example of the common place book not only ties these together but yields to the next topic; Serendipity.