You open a note you wrote eight months ago. You see “Important: review this with X’s approach” and you cannot remember what X was, why it mattered or what you wanted to review. The note exists, but it is useless.
This scenario is so common that many people conclude that taking notes simply does not work for them. The correct conclusion is different: the problem is not the act of taking notes, but how they are written. Most notes are written for the self of the moment, not for the self of the future. And the future self is, in many ways, a stranger who does not share the context you had when you wrote them.
The problem with today’s notes
When we take notes, we are in the middle of a cognitive flow. We have just read something, heard something or had an idea. The context is fresh and omnipresent; we do not need to write it down because it is already in our heads. So we take shortcuts: we write fragments, implicit references, abbreviations that make sense right now.
The result is notes that seem perfectly clear when written and are nearly unreadable weeks later. “See Sönke’s article” tells you nothing if you cannot remember which article, what argument it made and why you connected it to what you were thinking. “Idea for the project” could refer to any of the projects you had open at the time.
The error is not brevity itself. It is brevity without context. A short, well-written note can be perfectly useful months later; a long note full of implicit references can be useless within weeks.
The cost of useless notes is not just the wasted time of writing them. It is that when you search for something and find notes you cannot decipher, the whole system loses credibility. You stop searching because you do not trust you will find anything useful. And you stop taking good notes because you see no return.
The context that always gets lost
There are four types of context that evaporate quickly after writing a note:
Why you wrote it. What problem you were trying to solve, what question you had asked yourself, what caught your attention in what you had just read. This is the most valuable context and the one most frequently omitted.
What you already knew. When we read or hear something new, we understand it in relation to what we already knew. But when we review the note months later, we no longer remember what our prior understanding was. The note captures the conclusion but not the path.
The doubts you had. Open questions, parts you did not fully understand, hypotheses you wanted to verify. Without this, the note seems more certain and complete than it actually was.
The source and its reliability. Not all sources carry the same credibility. A note about study results needs to know whether that study was peer-reviewed, replicated, or had conflicts of interest in its funding.
Principles for durable notes
Write in complete sentences, not fragments. Fragments are efficient in the moment but ambiguous in the future. “Decisions under uncertainty: base rate” can mean dozens of different things. “Humans tend to ignore base rates when making decisions under uncertainty, leading us to overestimate scenarios experienced with intensity” is unambiguous.
Write the why, not just the what. The most valuable information in a note is usually not the fact itself, but the reason why that fact seemed important. “This idea is useful because it solves the X problem I had with my Y project” is an order of magnitude more valuable than the fact alone.
Include date and source. The date situates the note in time and helps distinguish whether the ideas were yours or came from a reading. The source lets you return to it if you need more context.
One idea per note. Notes that try to capture multiple related ideas tend to be confusing because each idea has its own context. Separating ideas makes each note atomic: complete in itself, without depending on the others to make sense.
Formats that work
There is no single ideal format. What does exist are structures that make notes comprehensible outside their original context.
Fact + interpretation + question. First, what you observe or learn (the fact). Second, what it means to you or what it implies (your interpretation). Third, what remains unresolved or what you want to explore (the question). This format forces you to go beyond passive transcription.
The note as a message. Write as if you were sending the note to someone who does not share your context. Not with the formality of a professional email, but with the clarity of an explanation to an intelligent person who has just arrived and knows nothing about the topic. This mental exercise forces you to make explicit what you take for granted.
Evergreen notes vs. flow notes. Flow notes capture what is happening now: ideas in progress, meeting notes, drafts. Evergreen notes are distilled ideas you want to keep long-term. It is useful to distinguish between the two because they have different quality standards. A flow note can be more imperfect; an evergreen note deserves more work.
The stranger test
There is a simple criterion for evaluating whether a note will age well: the stranger test. Imagine that someone who does not know you, who has not been inside your head this week and shares none of your implicit context, reads this note. Do they understand what it means, why it is relevant and what you are supposed to do with it?
If the answer is no, the note needs more work. Not necessarily more length, but more explicit context.
Applying this test at the moment of writing costs a couple of minutes. Not applying it costs much more when, months later, the note is useless and you have to rebuild the knowledge from scratch.
The future self who will read your notes is not lazy or dim. They simply do not share the information you had when you wrote them. Writing for them is an act of consideration towards yourself: an acknowledgment that the knowledge you build today is worth preserving well.
