I think the added value in this is that by doing it then you can get back to the learning process going on in your brain at the time you wrote about it and this could resonate with many other stored but half-forgotten memories (for example that project that you were working on when you wrote that note, bringing in additional information).

Moreover, nothing is more useful to the understanding of a subject than trying to explain it to someone else, including your future self (you can only say to have fully understand Relativity when you are able to explain it your grandparents? :) ) That's why I guess it's being seen as a good thing.