Tools for thought are not always intuitive
Because Tools for thought should be flexible in their use, they are often not intuitive for new users. Think about paper, it gives so much potential to structure our thoughts and ideas, but give someone a blank piece of paper and a pen and they may be unsure what to write. Some people develop complex note-taking systems while others fail to fully grok how they can use paper to their advantage.
The more flexible, the greater the possibility space. A tool that can accomplish anything is great for doing nothing—the internet is a great example. I wonder if this is simply a necessary quality of the most powerful and flexible tools for thought, or if it is simply a design problem.
I think there's something inspiring here about bullet journals, though I'm not sure I can fully articulate what it is. Something about the customizability and modularity. It still requires a bit of a learning curve, but bullet journaling is at its core pretty simple but can be extended with hundreds of "modules" that people design for themselves. It almost shares overlap with Hypercard, but where Hypercard democratized programming, bullet journals democratize the mind and productivity.
"plugins" and "modules" are one step towards more intuitive tools for thought. I can print out some empty sheet music to write some music upon. The layout and structure this gives me helps dictate the activity.
...Design for everything and you design for nothing
...Design for everyone and you design for no-one