Agreed, this is a big problem. I tried a paper zettelkasten to get around the taking notes and losing them problem, but my collection grew too big to maintain on paper. Because of that, I've been building Zettelgarden (https://github.com/Zettelgarden/Zettelgarden) to help and try to solve this problem for myself.

Among other things, it breaks your notes apart into facts and entities, then stores those along with embeddings. This helps surface things you've seen before since it makes and surfaces links based on individual things, instead of the text as a whole.

In case anyone is interested, I wrote a bit about the process here: https://nsavage.substack.com/p/facts-arguments-theses-buildi...