Its just an investment that may pay off in time in the future. Say you need to explain how to do something to a friend, if you write it up and keep it somewhere

Its just an investment that may pay off in time in the future. Say you need to explain how to do something to a friend, if you write it up and keep it somewhere you should never need to type out that same explanation again if you other friend needs it at any point in the future. For a bunch of stuff its useless, but for setting up systems, giving similar advice on a subject to multiple people, or teaching a concept it seems like a solid plan. Even if you just keep it in a text file and the public doesn't see it, it still saves you time.