How to Build Knowledge That Lasts
Learning is supposed to be hard.
I’ve been in school for most of my life. Preparing for the Chinese college entrance exam Gaokao was hard; I still have bad dreams about it. But it was only recently that I noticed how inefficient my learning had been.
As we get busier after school, effective learning becomes even more important. People often resort to quick-bite information due to FOMO, but this approach isn’t enough for a deep understanding.
If there is one takeaway, it’s this: Learning requires effort. It doesn’t come easy. You have to do the work for knowledge to accrue.
Learning takes effort
People say knowledge is food for the brain. The process is different.
We don’t simply gain knowledge as our bodies gain weight. It’s more like gaining muscle, which is an active, effortful process.
Learning itself requires deliberate practice, and I mean actual learning that helps us to increase our understanding of the world, not just the learning that makes us pass a test. And deliberate practice is demanding; it requires effort. […] “The one who does the work does the learning,” writes Doyle. “It is hard to believe, but in education that is still a revolutionary idea. 
Cramming is not effective
Many regret forgetting most of their reading, often due to cramming for exams, where they quickly absorb vast information.
It works, but only for a short time. It’s easy to notice the rapid gains, but not the rapid forgetting that follows.
This also explains why we default to rereading.
Rereading the chapter right after you’ve first read it can provide a deceptive familiarity. The words become more familiar, but you’re not truly grappling with the material—the so-called fluency fallacy. 
Durable learning requires time to transform short-term memory into long-term memory. Retrieval practice is at the heart of the process.
To learn is to retrieve
Retrieval practice involves actively recalling information from memory, not just reviewing the material.
Oddly enough, the best way to put information into your long-term memory is to try to retrieve it from your own long-term memory. 
To understand why, we need to step back and understand a bit of how learning works.
Consolidation is key
Learning involves at least three steps:
Encoding: Making sense of the information held in short-term working memory.
Consolidation: Connecting to prior knowledge and experience in long-term memory.
Retrieval: Updating the connections and enable you to apply it when you need it.
Learning is making connections to what we already know.
Prior knowledge is a prerequisite for making sense of new learning, and forming those connections is an important task of consolidation. 
Learning often starts as confusing, but consolidation helps organize and solidify learning. Retrieval not only strengthens the existing learning but modifies it.
Retrieval also provides feedback on how well we learn. A sense of familiarity does not mean mastery. You learn when you can retrieve, not when you think you know.
Learning capacity is unlimited, but retrieval capacity is limited. What we forget is less the memory itself but the cues to call it up easily.
Knowledge is more durable if it’s deeply entrenched, meaning that you have firmly and thoroughly comprehended a concept, it has practical importance or keen emotional weight in your life, and it is connected with other knowledge that you hold in memory. 
To learn something deeply, the process works more like a loop rather than a one-way process, as we’ll see in the following.
Applying the theory
Retrieval practice should feel hard
Thinking you’re doing something wrong when learning feels hard is a mistake. The greater the effort to successfully retrieve learning, the more this learning is strengthened. Conversely, the easier knowledge or skill is for you to retrieve, the less retrieval practice will benefit your retention of it.
After reading a page or a chapter, look away and summarize the key ideas. You can think out loud or write them down. You can even do this before reading: note down what you know on a blank sheet of paper and keep adding to it after each reading session.
Make flashcards to do spaced repetition practice (e.g. Anki).
Space out, interleave, and vary your practice
Spacing out practice sessions makes them more effortful, but more effective. It also allows consolidation to kick in if you sleep on it.
Studies find that it’s more effective to delay subsequent retrieval practice after the initial test. And we should repeat the practice if we want knowledge to stick.
Interleaving not only creates spacing but also helps you understand the differences between different kinds of problems and know which tool to use.
Mix questions and notes about different topics and disciplines. For example, use a single deck in Anki, and be conscious about organizing notes by topics or tags.
Alternate topics. Instead of using two hours to read the same book each day, switch to another one for the second hour. (But also know that excessive context switching can lead to cognitive overload.)
Employ different ways of practicing the same skill: different sequences, different representations, or in different situations.
People who learn instruments are familiar with this: you can change the tempo, the rhythm, or even play with a different hand.
Use memory tricks, or mnemonics, such as acronyms and vivid images. For example, when learning mental models, you can create an image for each model.
Annotate as you read, instead of highlighting:
Key ideas rephrased in a way as simply as you can
Relationships between key ideas
Examples or stories from your experience
Potential test questions
What you don’t understand or need further research
Elaborate out loud or discuss with others
Structure-building is the ability to discern key points, knowing whether it’s relevant to the main ideas (fit or doesn’t), and how (whether it adds nuances, capacity, and meaning, or it obscures.) It helps consolidation as new learning can connect to some structure of things that we already understand.
For example, preview the material before diving into details. Even if you may not feel you learn much, it’s easier to put together a jigsaw puzzle when you’ve already seen the complete picture.
But not too hard
We should aim for an appropriate level of difficulty. Pressing through a book is not only painful but ineffective. Your effort pays off when you manage to overcome difficulties with increased effort.
If it’s too difficult, make it easier. If you’re struggling with a book, put it down and find a simpler one. Get an introductory book, or watch YouTube videos. Start with the simplest questions and work your way through harder ones. It’s like building a structure. Remember that we learn when we can connect the learning to prior knowledge.
Other important stuff
Learning doesn’t happen only when we sit down and learn. Sleep and rest are often overlooked. For example, taking short breaks after a session allows us to transfer what we’ve just learned to long-term memory, but we tend to skip it because we can’t feel the process taking place.
Nutrition and exercise also enhance learning. BDNF produced after exercise makes it easier to create new neural connections.
Most of our learnings are declarative — we engage our working memory to consciously learn something. But there is another learning system called procedural, like how to ride a bike becomes automatic when we’ve learned it.
What’s surprising is that the procedural system involves in non-motor skills too, including writing, language, and math. It’s about developing intuition that enables us to make quick judgments.
I thought intuition only came by chance, but it seems there can be ways to train it, such as by internalizing key, exemplar questions. I’ll explore this more after I gain more understanding.
I’d also like to experiment with mnemonics and give more attention to building structures in my learning journey.
I hope this is helpful! What learning strategies have worked for you? Feel free to share thoughts or questions, or connect on X.
Until next time,