The Case for Writing Things Down That You Already Know

There's an assumption underneath most productivity advice about note-taking: that notes are for capturing things you learned from outside yourself. Articles you read, talks you attended, podcasts you half-listened to on a run. Information comes in, you file it, you retrieve it later.

This is useful. It's also incomplete.

Writing as a thinking tool, not a storage tool

The more interesting use of notes isn't to capture what you've read. It's to find out what you think. And the only way to do that is to write — without a source, without a prompt, without a course or a framework telling you what conclusions to reach.

This is uncomfortable. Writing from your own thinking feels slower than summarising an article. There's no external scaffold. The quality of the output depends entirely on the quality of your reasoning, which is exactly why most people avoid it.

But it's also where the most durable notes come from. A note that captures something you genuinely think — an observation, a conviction, a question you can't resolve — is worth more than fifty notes summarising other people's arguments about it.

The surprise of rereading

The other argument for writing down things you think you already know: you often find out you don't know them as well as you thought.

Try writing a clear, one-paragraph explanation of a concept you feel confident about. The places where the explanation gets vague or circular are the places where your understanding is actually thin. Writing reveals this in a way that reading about the topic again doesn't.

What this looks like in practice

It doesn't have to be formal. The most useful version of this is just a periodic habit — every week or two, writing a few paragraphs about something you've been thinking about, something you've changed your mind on, or something you believe that most people around you don't.

Over time, these notes become a record of how you think, not just what you've consumed. That's a more interesting archive — and a more useful one.