Ask HN: How to remember technical topics which you don’t use/refer everyday?

Take notes about the most important parts of what you learnt. That way when you have to recall a topic you don't have to reread the whole book or tutorial but just your notes.

Spend 80% of your time building / practicing, and 20% reading / researching.

This doesn't apply to everyone—if your goal is just the pursuit of knowledge then you can disregard this advice. For me though, the satisfaction and the cementing of knowledge comes from its application. Especially as I get older and realize the ephemeral and fleeting nature of body and mind, it just reinforces the need to be in the moment and cultivate focus on doing rather than optimizing against (or fighting!) my human limitations.

Thank you especially for linking the Augmenting Long-Term Memory post. I'm just on the part going through the author's usage of Anki and it has already inspired me to download the client and try it myself as well. I don't think I'll put nearly as many things in it as the author says he does, but it sounds like it can be an incredible tool for whatever we find worth remembering.

Update: After reading the API section of this post, I found this very last part interesting in the context of OP's question[0]. I thought it may be worth highlighting to the OP that even a heavy user of a memory system recognizes that knowledge we don't regularly use may not be worth remembering.

[0]"A more challenging partial failure mode is Ankifying what turn into orphan APIs. That is, I'll use a new API for a project, and Ankify some material from the API. Then the project finishes, and I don't immediately have another project using the same API. I then find my mind won't engage so well with the cards – there's a half-conscious thought of “why am I learning this useless stuff?” I just no longer find the cards as interesting as when I was actively using the API.

This is a difficult situation. I use the rule of thumb that if it seems likely I'm not going to use the API again, I delete the cards when they come up. But if it seems likely I'll use the API in the next year or so, I keep them in the deck. It's not a perfect solution, since I really do slightly disconnect from the cards. But it's the best compromise I've found."

I use this https://zim-wiki.org/

Take notes. Use the Search feature when you need to dig information out.

Memorization is most often useless. Focus on understanding instead.

You need to only retain information that can help you derive useful conclusions, and your mind is most likely smarter than you at that.