There are people who write their own notes in short hand regardless of whether someone else will be able to read them because short hand is more efficient.
I think it’s possible for a whole language to be simply nicer than the established languages so that it would encourage you to write your own notes to yourself in that language.
Esperanto is relatively easy to learn but it doesn’t perform better in some niche in a way that would encourage people to use the language for that niche.
There are people who write their own notes in short hand regardless of whether someone else will be able to read them because short hand is more efficient.
I think it’s possible for a whole language to be simply nicer than the established languages so that it would encourage you to write your own notes to yourself in that language.
Esperanto is relatively easy to learn but it doesn’t perform better in some niche in a way that would encourage people to use the language for that niche.