Remembering books is a pain in the a**.

I have been puzzled by the question of how to assimilate books. Not in the means—there are indeed means—but the practicality of it. Reading through a book is one thing, while retaining it is another.

When we read through books, we're typically remembering about 30% of the content. That remembering fades over time. How much of your college books do you remember? High school history books? If you're like me, only a small fraction stays with you.

I have fallen into a recent obsession, a fixation on discovering how I can retain information, and install knowledge into long-term memory. There are brute force methods: read the book twice, three times, compile a list of study questions, and review them daily. But there's an inelegance to brute force methods. They don't fit into modern life. It's not a real solution if it's not something executable.

I've been experimenting with different means of remembering, expanding my knowledge and retention through a couple of strategies. The first has been through spaced repetition techniques. Anything—any word or concept that I do not know when I am reading something—I underline and dog-ear in the book. I later return to that and capture it as a flashcard. The most recent one was the word "apostasy," where I made a flashcard like this:

Front: Apostasy
Back: The act of abandoning or renouncing a religious belief, faith, or allegiance.

I put that into Anki, a spaced repetition software, and it goes into my regular pipeline of memorization practice. Anki is worth a whole post on its own—why to use it, how to use it—and I certainly wouldn't be the first to tout its virtues. I'll leave that for another day. Suffice it to say, I put this information into a set of flashcards that I review regularly, usually at the gym in between reps or in a pretty place outside.

Simple flashcards were a bit lacking though—they weren't able to quite capture information fully for me, especially if the concept was large. I've been working a lot more with "cloze" type cards—essentially mad-lib style, fill-in-the-blank cards—that are a body of text where I fill in certain words. A recent one of those looks like this, where all the {{cN::}} sections are the fill-in-the-blank spots:

A {{c1::gradient}} is a {{c2::vector}} that points in the direction of the {{c3::greatest increase}} of a {{c4::function}} and whose {{c5::magnitude}} represents the {{c6::rate of change}} in that direction.

Often I'll put in large bodies of text, and I don't expect myself to remember all the words. That's not actually the important part for me. The important part is the repeated exposure to the concept and the active engagement—I have to think about the concept again to fill in the blank. I often get these wrong—a lot of times the word itself doesn't matter—but I am reintroduced to the concept, and that is good enough for me to have a solid understanding integrated into my brain. There are few circumstances in which I need to actually reproduce an exact definition, so I don't prioritize that level of expertise for a lot of concepts.

Now here's the approach I've been loving, and that's a combination of definition and cloze to learn a word or concept. For example, when I was taking a deep dive into learning Machine Learning algorithms and the AI landscape, there were a lot of new concepts to tackle, especially around algorithms. One of my favorites to learn was Stochastic Gradient Descent. At first, I made a standard, reversible flashcard that looked like this:

Front: Stochastic Gradient Descent (SGD)
Back: An optimization algorithm that updates model parameters by calculating the gradient of the loss function.

The problem was that I would often get it wrong. I could not reproduce the whole definition. I would get frustrated. But I really wanted to learn it, I did not want to just give up. So, how could I break it down further? Well, I could make reversible flashcards for each part of the word: for Stochastic and Gradient (Descent seemed pretty self-explanatory). Ok, good. And then came the cloze to tie it all together!

{{c1::Stochastic}} {{c2::Gradient}} {{c3::Descent}} ({{c4::SGD}}) is an {{c5::optimization}} {{c6::algorithm}} that updates {{c7::model parameters}} by calculating the {{c8::gradient}} of the {{c9::loss function}}.

This exploration of Anki has been underpinning my desire to consume knowledge through books. I haven't quite cracked the nut on how I like to best retain information from books, but I'm excited about how it's started. Let's explore that together for a minute.

One problem with books is that they often don't come with a study pack of words and flashcards. It's reasonably easy to pick out words or concepts and definitions in the books, later placing them in flashcards. Sometimes the authors make it easy with a clear and concise definition of a concept they introduce, and most other times I have to dig for a definition or a word or concept. That's all fine. Flash-cardable enough.

The bigger problem is trying to capture the overall narrative, concepts of the book that live outside word and definition pairs. A lot of information is delivered through storytelling. There might be a takeaway, but it's often challenging to pack it into a sentence or two. You might be thinking to yourself—as I am now—"well, of course you can distill it if you think about it! Just concentrate, reflect, and write your own set of sentences to capture the essence of the concept."

What ends up happening though is that there are too many concepts to capture, and as I'm going through the book, I don't know which ones I need to capture or that are worth retaining. I usually don't know that until after I'm done, at best. Taking time to distill information for each concept, each piece, well... I leave that to the doctoral students out there. It's a whole job in itself! Honestly, to me, it feels like a great luxury—I love the learning and the nerding—but among a set of responsibilities that includes a job, fitness, art, and a full social life, spending such focused energy and time is not reasonable. In my lived experience, it doesn't get done. It's a brute force, inelegant solution.

I'll emphasize, I'm here to disappoint because I don't have an alternative! I like the idea of creating personal book summaries that I can return to whenever I want to revisit a book (rather than reread the whole damn thing) or share concepts from it with others. Nothing is as infuriating as asking, "what is the book about?" and being told, "well, you just have to read it." Yikes, let's spare others that level of banal suffering.

In lieu of detailed summaries, or as a companion to them, I am experimenting with collecting quotes from books I read. I mark sections with a pen and then dog-ear the page to return to later. Fair warning to all friends—do not give me your books if you care about them looking pristine, I will destroy them with my active markings. I then go back through those sections, usually accompanied by a PDF or text doc of the book that I've found on the internet, and then go about copying the quotes to a text doc. From there, I'll set up a JSON structure that I want the quotes to follow. Something like this:

{ "text": "The greater grief comes from the consequent anger and pain, rather than the original causes of our anger and pain.", "title": "Consequent Grief", "description": "A reflection on how the aftermath of emotions often causes more pain than the original event.", "tags": ["Grief", "Anger", "Pain"], "citation": "11:8.8" }

Thank the gods for recent technology where I can ask an LLM to do the lion's share of the data conversion work. I ask it to decide on a title, description, and tags—and to then spit out the JSON for me. It's not perfect, but it gets the job done at a B- level for titles, descriptions, and tags. Good enough—better that than never done!

I finished my first read of Marcus Aurelius's Meditations yesterday and collected a number of quotes that resonated with me. It's more than expected, so I'm hoping to find a better way to consolidate either through themes or marking favorites. That said, it's my first foray into this experiment, and I'm excited to be able to capture and share all the parts that resonated with me in one way or another. I love the shareable nature of it, and I love that this is now part of my permanent knowledge store, a special place in my digital garden.

How do you like to retain knowledge and information? How do you remember the books you read? If you have strategies and suggestions, please reach out. I'd love to hear from you!

Below is an example of one of my markings in Meditations. Simple but effective!