How to Take Smart Notes by Sönke Ahrens


🚀 The Book in 3 Sentences

  1. While reading, take notes (1 note per idea) in your own words.
  2. Collect your reading notes in a "slip-box" of notes (or "the Zettelkasten"), and add new notes behind related existing notes.
  3. Use the notes in your slip box to write “bottom-up” (i.e., organizing existing notes into a structured piece) and create connections between related ideas.

🎨 Impressions

The ideas in this book (e.g., Zettlekasten, bottom-up writing, and the importance of writing on learning) are well constructed and make logical sense. I've personally experienced that when I interact with the texts I read in the form of taking notes in my own words I naturally better comprehend the material.

As an example, I've found that just in the 5 months of creating these book notes, I'm much better at recalling the ideas from the books I published notes on vs. ones that I read previously, even in 2020.

While the Zettlekasten approach makes logical sense, I feel like there is still a bit of a barrier to integrate the strategy within my current knowledge management solution. I'd like to incorporate it into my existing Notion setup but I'll have to do further research on the least disruptive way to do that.

How I Discovered It

Ali Abdaal said this book transformed his relationship with note-taking.

Who Should Read It?

Anyone who reads a lot would benefit from reading this. In particular, students who have to read academic texts and then write papers on them would really benefit from the "slip-box" strategy.

I wish I had read this book prior to my university experience.

☘️ How the Book Changed Me

How my life / behavior / thoughts / ideas have changed as a result of reading the book.

  • Concretize ideas by writing notes in your own words: Highlighting certain parts of books is ok, but rephrasing the author's idea into your own words is where the learning really happens. At a macro level, this is what I'm doing with these book notes, but Ahrens suggests taking notes while reading and then make the notes permanent/polished after you finish the book.
  • Create a slip-box of related notes: I like the idea of a slip-box of notes (or the "Zettlekasten"). It makes more sense to keep all of your literature notes in one relational database rather than across various sources (Kindle highlights, Notion pages, etc.). Now it just comes down to how to implement the system.
  • Build articles "bottom-up" rather than "top-down": Building articles from a set of previous notes makes the development process much less daunting. If you basically already have a first draft created from an outline all you really have to do is connect the pieces and polish.

✍️ My Top 3 Quotes

  • "We have to choose between feeling smarter or becoming smarter. And while writing down an idea feels like a detour, extra time spent, not writing it down is the real waste of time, as it renders most of what we read as ineffectual."
  • "Writing is, without dispute, the best facilitator for thinking, reading, learning, understanding and generating ideas we have."
  • "A truly wise person is not someone who knows everything, but someone who is able to make sense of things by drawing from an extended resource of interpretation schemes."

📒 Summary, Highlights, and Notes

Kindle Highlights

a system is needed to keep track of the ever-increasing pool of information, which allows one to combine different ideas in an intelligent way with the aim of generating new ideas.

Location: 224

Studies on highly successful people have proven again and again that success is not the result of strong willpower and the ability to overcome resistance, but rather the result of smart working environments that avoid resistance in the first place

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Whenever he read something, he would write the bibliographic information on one side of a card and make brief notes about the content on the other side (Schmidt 2013, 170). These notes would end up in the bibliographic slip-box.

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In a second step, shortly after, he would look at his brief notes and think about their relevance for his own thinking and writing. He then would turn to the main slip-box and write his ideas, comments and thoughts on new pieces of paper, using only one for each idea and restricting himself to one side of the paper, to make it easier to read them later without having to take them out of the box.

Location: 421

He did not just copy ideas or quotes from the texts he read, but made a transition from one context to another.

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The trick is that he did not organise his notes by topic, but in the rather abstract way of giving them fixed numbers. The numbers bore no meaning and were only there to identify each note permanently.

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We need a reliable and simple external structure to think in that compensates for the limitations of our brains.

Location: 457

Writing is, without dispute, the best facilitator for thinking, reading, learning, understanding and generating ideas we have.

SA Note: The basis and hypothesis behind starting

Location: 494

If you want to learn something for the long run, you have to write it down. If you want to really understand something, you have to translate it into your own words. Thinking takes place as much on paper as in your own head.

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Do not brainstorm for a topic. Look into the slip-box instead to see where chains of notes have developed and ideas have been built up to clusters.

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The reference system has two purposes: To collect the references (duh) and the notes you take during your reading. I strongly recommend using a free program like Zotero, which allows you to make new entries via browser plugins or just by entering the ISBN or digital object identifier (DOI) number.

Location: 636

You will find the links to all recommended programs on

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you will improve your reading, thinking and other intellectual skills just by doing everything as if nothing counts other than writing.

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In the old system, the question is: Under which topic do I store this note? In the new system, the question is: In which context will I want to stumble upon it again?

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The slip-box is designed to present you with ideas you have already forgotten, allowing your brain to focus on thinking instead of remembering.

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Fleeting notes are only useful if you review them within a day or so and turn them into proper notes you can use later.

SA Note: This is my process of highlighting in kindle but then transforming those highlights into actual notes in my own words in the book note template

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Permanent notes, on the other hand, are written in a way that can still be understood even when you have forgotten the context they are taken from.

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The notes are no longer reminders of thoughts or ideas, but contain the actual thought or idea in written form. This is a crucial difference.

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The key to creativity is being able to switch between a wide-open, playful mind and a narrow analytical frame.”

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the Zeigarnik effect: Open tasks tend to occupy our short-term memory – until they are done.

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we also know that we don’t actually have to finish tasks to convince our brains to stop thinking about them. All we have to do is to write them down in a way that convinces us that it will be taken care of.

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we can use the Zeigarnik effect to our advantage by deliberately keeping unanswered questions in our mind. We can ruminate about them, even when we do something that has nothing to do with work and ideally does not require our full attention.

SA Note: Takeaway - make sure the banal tasks (like a shopping list) are written down, but keep the big questions you are ruminating on (like strategy or bigger decisions) in your mind as you do menial tasks. Good "lawn mowing" material, i.e., problems to work out as you are mowing the lawn.

Location: 1318

most organisational decisions can be made up front, once and for all, by deciding on one system. By always using the same notebook for making quick notes, always extracting the main ideas from a text in the same way and always turning them into the same kind of permanent notes, which are always dealt with in the same manner, the number of decisions during a work session can be greatly reduced. That leaves us with much more mental energy that we can direct towards more useful tasks, like trying to solve the problems in question.

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Confirmation bias is tackled here in two steps: First, by turning the whole writing process on its head, and secondly, by changing the incentives from finding confirming facts to an indiscriminate gathering of any relevant information regardless of what argument it will support.

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Being able to re-frame questions, assertions and information is even more important than having an extensive knowledge, because without this ability, we wouldn’t be able to put our knowledge to use.

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deliberate practice

SA Note: Many references throughout to the content of Peak and "deliberate practice"

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We have to choose between feeling smarter or becoming smarter. And while writing down an idea feels like a detour, extra time spent, not writing it down is the real waste of time, as it renders most of what we read as ineffectual.

Location: 1591

There is a clear division of labour between the brain and the slip-box: The slip-box takes care of details and references and is a long-term memory resource that keeps information objectively unaltered. That allows the brain to focus on the gist, the deeper understanding and the bigger picture, and frees it up to be creative. Both the brain and the slip-box can focus on what they are best at.

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What does help for true, useful learning is to connect a piece of information to as many meaningful contexts as possible, which is what we do when we connect our notes in the slip-box with other notes. Making these connections deliberately means building up a self-supporting network of interconnected ideas and facts that work reciprocally as cues for each other.

Location: 1887

Add a note to the slip-box either behind the note you directly refer to or, if you do not follow up on a specific note, just behind the last note in the slip-box.

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  1. Add links to other notes or links on other notes to your new note. 3. Make sure it can be found from the index; add an entry in the index if necessary or refer to it from a note that is connected to the index. 4. Build a Latticework of Mental Models

Location: 1961

In the Zettelkasten, keywords can easily be added to a note like tags and will then show up in the index. They should be chosen carefully and sparsely. Luhmann would add the number of one or two (rarely more) notes next to a keyword in the index

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The archivist asks: Which keyword is the most fitting? A writer asks: In which circumstances will I want to stumble upon this note, even if I forget about it? It is a crucial difference.

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Keywords should always be assigned with an eye towards the topics you are working on or interested in, never by looking at the note in isolation.

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A truly wise person is not someone who knows everything, but someone who is able to make sense of things by drawing from an extended resource of interpretation schemes.

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“Creativity is just connecting things. When you ask creative people how they did something, they feel a little guilty because they didn’t really do it, they just saw something.” (Steve Jobs)

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Most often, innovation is not the result of a sudden moment of realization, anyway, but incremental steps toward improvement. Even groundbreaking paradigm shifts are most often the consequence of many small moves in the right direction instead of one big idea. This is why the search for small differences is key.

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The biggest threat to creativity and scientific progress is therefore the opposite: a lack of structure and restrictions. Without structure, we cannot differentiate, compare or experiment with ideas. Without restrictions, we would never be forced to make the decision on what is worth pursuing and what is not.

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It is not surprising that motivation is shown to be one of the most important indicators for successful students – next to the feeling of being in control of one’s own learning course.

SA Note: This is what entrepreneurship is, you are literally choosing what you have to learn next based on your strategy and decisions.

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Another key point: Try working on different manuscripts at the same time.

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It is like martial arts: If you encounter resistance or an opposing force, you should not push against it, but redirect it towards another productive goal. The slip-box will always provide you with multiple possibilities.

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For every document I write, I have another called “xy-rest.doc,” and every single time I cut something, I copy it into the other document, convincing myself that I will later look through it and add it back where it might fit. Of course, it never happens – but it still works.

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