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

138 points by aecs99 ↗ HN
There are a ton of topics I learn/read on a daily basis. Some are out of my personal interest, some out of need (when interviewing).

I notice that after a while, without enough usage, these topics simply evaporate from my memory. I know the simple answer is to keep practicing.

I’m interested in knowing how different people do this. Looking for any tips, hacks, etc.

81 comments

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I have a personal private knowledge base, built using mediawiki.

It’s easy to add content to and supports code highlighting, images, files and all the nice things you’d see on wikipedia. And has a beautiful skin (template) with gorgeous typography that’s a joy to read.

I also use it for tech notes, among the other stuff.

I print them out on paper, then add them to my library. Brain just does the rest.
Anki spaced repetition software
I don’t. If I’m not actively using something then it just gets evicted from cache.

I generally remember the difficult/weird parts that made initial learning slow, everything else I just re-learn as needed from the same sources that I used initially.

For it I simply need to find them interesting. That causes me to spend time researching or studying them. And that means I have them at my finger-tips for conversation or application.

This may include downloading papers or buying textbooks or equipment to hack (when appropriate).

Sorry for the non-answer answer I'm about to give, but I don't really think you should have to keep these things in memory. At some point it becomes a waste of memory space (at least that's how I experience it).

There ARE some topics I want to remember, and those I try to put in writing. Both because it helps them stick in my mind for longer and because then I have a reference to go back to if I need a refresher. I use my own blog quite a bit to remember ways to do things that I may have figured out earlier and then forgotten.

But in terms of keeping things completely in memory: I have grown to think that, for a healthy mind, the things worth remembering are the things we remember. It's _good_ to remember things you're regularly using. If you're not regularly using them, you may as well forget the details and refresh your memory later if needed. Of course the major caveat being that this is within reasonable limits and not a symptom of an illness or actual serious memory loss.

It is a balance, and losing my memory in general is one of my worst fears. I guess it is a matter of deciding if these topics are beginning to evaporate sooner than you're comfortable with. Do they disappear after a day? A week? A year? If I start forgetting knowledge too quickly for my standards, that's when I'll get worried. It's just a matter of deciding what "too quickly" is for us.

Outside of pathology, the mechanism of forgetting seems pretty important: https://en.wikipedia.org/wiki/Hyperthymesia

>Hyperthymesia, or highly superior autobiographical memory (HSAM), is a condition that leads people to be able to remember an abnormally large number of their life experiences in vivid detail.

>Hyperthymestic abilities can have a detrimental effect. The constant, irrepressible stream of memories has caused significant disruption to Price's life. She described her recollection as "non-stop, uncontrollable and totally exhausting" and as "a burden".[1] Price is prone to getting lost in remembering. This can make it difficult to attend to the present or future, as she is permanently living in the past. Others who have hyperthymesia do not display any of these traits, however.

I've beaten myself up many times in college for seemingly forgetting everything after classes finish. I spent a bunch of time trying to figure out how to learn and retain better. I tried Anki a bit but would inevitably forget things as soon as I stopped too. Forgetting is frustrating, and a situation where I -know- that I knew something before but not anymore is doubly so. But.. ultimately I think I've arrived at this view as well.

Your brain is not wired to remember things that you don't use. If you want to continue remembering, you have to continue engaging with the topic, and a lot of the advice in this thread is IMO just that (just, with a specific regimen / kind of engagement). It's completely natural to forget.

In fact, I'd go further and suggest embracing the forgetting and relearning cycle. If you really need to revisit the topic, you can relearn it again, and it'll be faster than the first time. And maybe you'll forget another time -- that's OK too, you can pick it up again even faster. In the end it's the discipline of relearning (the particular topic, and in general!) that actually continuously hardens. IMO there are parallels between this mindset and SRS -- though without the shame when you forget or miss a day of practice.

I search on Google and find my own articles I wrote about those topics in the past.

Strange, but funny feeling.

Learn the basics of how human memory works, and techniques for making knowledge stick in long-term memory. Here's a few resources that teach this at an approachable level:

[1] A Mind for Numbers (book): https://barbaraoakley.com/books/a-mind-for-numbers/

[2] Learning How To Learn (Coursera course): https://www.coursera.org/learn/learning-how-to-learn

[3] Make It Stick (book): https://www.retrievalpractice.org/make-it-stick

[4] Augmenting Long-Term Memory (blog post): http://augmentingcognition.com/ltm.html

[5] SuperMemo Guru (website): https://supermemo.guru/wiki/SuperMemo_Guru

[6] Nelson Dellis (YouTube): https://www.youtube.com/channel/UCnINhoHWuVjUDXp7dav5e3A

I second the use of Anki--it's a great tool. Other (non-free) options include SuperMemo and IDoRecall.

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."

Great points. I agree that one of the challenges is identifying what knowledge is worth investing the time to bake into long-term memory.

Paying attention to what knowledge I (or top performers) use most often in practical projects / everyday work has helped. I also try to identify fundamentals; i.e. chunks of knowledge that experts in a field have identified as critical to understanding that field.

Third-ing the use of Anki, and I found it weirdly inspirational to watch YouTube videos of how Med Students use the system. It's some combination of being energized by their go-getter attitude, and being deeply relieved that I'm not in their shoes
Forthing the use of Anki. I actually do most of my studying on mobile, using Ankidroid. And though it works great on a regular LCD phone, I absolutely love it on an E-Ink ebook reader. I personally use the Barnes and Noble Nook, because you can install Ankidroid and a launcher in ten minutes without root on that device.
By keeping pointers to the content rather than the actual content ;)
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.

I write cheatsheets. Just the bare minimum stuff needed to get things done. When I refer back to them it's a lot faster than looking things up again in (e.g.) stackoverflow. My pandas cheatsheet gets probably too much use (damn that API).
When you learn something more in depth, you are less likely to forget it.

When you learn other things adjacent to the topic at hand, but related in some way, you’re less likely to forget things as you build more and more of a frame of reference around it.

But either way, the key to remembering things for a very long time is spaced repetition. First you need to test your recall after a short period, then after a longer period, etc.

Memorization skills isn’t something you’re inherently good or bad at, or are born with: it’s a skill you can absolutely learn!

I take notes in a journal for this type of stuff since the odds are good I will lose the link to whatever it was or the old site will be gone the next time I look for it.
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.

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I’ve given up staying up-to-date on everything and limited myself to things I can apply or are direct alternatives to technologies I use. Things like Meta’s approach to caching on Facebook and stuff are interesting but only really relevant for less than a dozen people and I reckon a waste of time for most others. If I skip that I can mull longer on the topics relevant for me.
I have a Notes folder containing 'subject' text files. Notes/crypto.txt Notes/docker.txt Notes/equity.txt ... anything and everything one day I'll divide them into subfolders Notes/geopolitics/zeihan.txt Notes/programming/languages/rust.txt

if a text file isn't good enough, or there needs to be an image embedded, I use other file types

And a Documents folder containing 'subject' article files. Documents/Programming/Languages/Rust ...

I do the exact same thing. Its been very effective. Looking at something I wrote myself refreshes my memory a lot more than any other kind of resource.

I personally use markdown files in the event I want to publish one of my notes. It also let's me inline images and see them if my editor supports previewing.

I’ve been meaning to try bear.app for this reason. Have never got past notes.app though.
The goal should be to know what you don’t know, because you can’t ask questions about the things you don’t know that you don’t know.

So forgetting is ok, as long as you remember that there was something extra the next time you meet the same problem.

This. It reads like the answer to dunning Kruger.
Just be honest when talking about these things. No one knows everything, so people will appreciate the humility as well as the eagerness to adopt new tech.

Keep refreshing HN to keep up to date, but realize any engineer worth his salt can figure out new tech in a week or two. No need to be an expert.

Sometimes, the fate and knowledge of an engineer can be decided by PM ticket assignment. Side projects are good to keep you sharp, but don’t stress. Once you move to management or team lead, you’ll realize that a competent engineer will always deliver results.

Don't. Let them fade. Reread the docs when you need them. The amount of brain space you'd need to keep rarely used topics fresh is unimaginable. Relearning to ride a bike is easier than learning the first time (unless you've had a stroke). You'll pick it up again. Learn for the sake of learning and let go. All you need to maintain is the references and meta data.
I leverage technology to replace memory. Details don’t matter if I know a thing exists and I’m good at finding things. Finding things is a far more useful skill to develop than memorization.

It is highly unlikely I’ll end up in a situation without cell signal, I carry an iPhone, Kindle Paperwhite, and a cellular iPad Mini (256gb) literally everywhere. (Handbags are awesome.)

On the off chance, I’m away from the internet and my kindle doesn’t have a useful book, I have all of Wikipedia and Wikitonary downloaded in Kiwix on my iPad Mini, downloaded PDFs in Dropbox, and a bunch of books in the D&D Beyond app, and videos in Youtube, because why not.

Any thing I need to remember is in Apple Notes or Scrivener. (All my research for stories is in a project file.)

I know this will sound negative but I think the appropriate answer is that you are very misguided.

One thing to realize is that rapid technology deployment and improvements mean we must adapt our approach to learning and problem solving if we want to be effective.

With the internet and exponential increase in software development tools, the amount of information is massive. And of course, we now have Google and Stackoverflow etc. which are extremely effective ways to solve problems or very quickly refresh your memory on the exact details that are relevant.

If you operate as if those things haven't changed, then you will not be effective.