That is interesting. If it's light and fast enough to launch quickly when you need it, it could be a very fun way to take notes.
We've tried imagining writing things in a book and then remembering the book, but it's hard to tell if we forget something recorded that way. Given that i cannot remember what the last thing we wrote was, it's probably not a very reliable method.
Most of the notes we take are just on a piece of paper we always carry. What makes them unusual is that they're not written in the Latin alphabet, they're written in a constructed script we invented for privacy.