This little snippet is from the section One Sentence Summary in the chapter How to Write Good Notes.
You will read from other sources that a Zettelkasten is idiosyncratic. It can hardly be understood by another person. The reasoning is that you write in your own Zettelkasten in such a way that only you can really understand. But the thought of the future self does not allow such a weak position: You are not yet who you will become. The future self is someone other than oneself. Technically, we always write for someone other than ourselves. It is difficult to be understood – even by yourself. If you write in such a way that you can be understood by as many other people as possible, there is a high probability that you will understand yourself later, too. In the span of two decades we all (hopefully) develop considerably. We are not just a little bit different. We are (hopefully) a completely different person. Arrange your Zettelkasten in such a way that anyone could operate it.