You probably already know about it, but I had never heard of it. Basically it’s hypertext without needing computers — just notecards and paperclips, though software is certainly allowed. In an official description it’s “a holistic method on how to deal with knowledge in your life.” More thoroughly, the OP says:
A Zettelkasten is a personal tool for thinking and writing. It has hypertextual features to make a web of thought possible. The difference to other systems is that you create a web of thoughts instead of notes of arbitrary size and form, and emphasize connection, not a collection.
There’s something appealing about that — I think. It’s just hard to wrap one’s thoughts around. But I’ll have to try it. After all, as the OP points out:
It is like swimming. If you can’t swim, you won’t be having any fun at all. Swimming sucks if all you do is float (or even sink) and fight the water. But boy, if you figure out the technique and glide through the water, it is incredible. But you don’t learn swimming by aiming for ease and fun. You learn to swim by aiming to be fast and graceful.
So I guess we can’t just read about it. (It’s complex. It’s German, of course.) OK, OK, I’ll give it a try.