With a [personal] wiki, you may have a random idea and write it down on your home page because you don’t know what else to do with it. Some time later, you have a second idea that goes with it, and now you can move the two thoughts off together on their own new page. Now suddenly more things will come up that belong on that page—you have a place to put it, and your mind will happily oblige.
Once you have a place to put some type of thought, you’ll get more thoughts of that type. Whether it’s a wiki or a paper journal, note cards, or shoe boxes, having a place for ideas in a specific topic area or project is a major benefit of an exocortical system.