I think Github Gists are among the most underrated tool out there for thinking clearly. Because it is GitHub, people associate it with codebases. But this is more than that. It is a utility for both technical and non-technical folks makes it a good place to document things.
I use it as a way to document my journey in learning code. Things are version tracked, making it great to head back and look at the journey of your understanding.
Since Google announced that Docs, Sheets, and Slides count toward your account storage, I've doubled down on Notion and like. You don't need to login in order to put together a gist. Just head to gist.github.com and start typing away.
Among numerous benefits, these are why I've been using Gists: