“Second brain” is one of those phrases that gets used a lot and understood very little. It's not a magic app, and it's not yet another place to pile stuff up. It's a precise idea, with a long history behind it, and a concrete promise: to free your head from the job of remembering, so it can go back to doing what it does best — thinking.
The problem: we capture a lot, we remember little
Every day ideas, notes, links, things said in meetings and shower thoughts pass through us. Human memory, though, isn't an archive: it's reconstructive, it forgets quickly and — worse still — it loses the connections between things. The result is that frustrating feeling: “I've thought about this before… but where did it go?”.
The problem isn't the amount of information. It's that we treat it as disposable: we capture it (maybe) and then abandon it in a notes app that turns into an attic. The more you pile up, the less you find. The attic isn't a second brain: it's just a messy first brain, outside your head.
What a “second brain” is
A second brain is an external, trusted system where you put what you think, knowing you'll find it again and that it will connect to everything else. It's not a recent invention: it's related to personal knowledge management and to historical methods like the Zettelkasten — the “slip box” the sociologist Niklas Luhmann used to write dozens of books by linking thousands of notes together.
The key word is trusted. A system only works if you trust it enough to offload your thoughts into it without hesitating. If every time you have to decide “where does this note go”, the friction will make you quit within a week. That's why a good second brain has a single entry point and zero bureaucracy: you drop things in, and the order comes later.
Don't file: connect
Here's the difference that changes everything. Filing means putting away and forgetting. Connecting means every new note wakes up the old ones. An isolated note is worth little; a note that brings back three things you'd already thought is worth a great deal — because that's where ideas that are truly yours are born, at the crossroads of distant notes.
It's the same logic as the intertwining threads that gave Itomori its name (if you're curious, I told that story here). The value isn't in the single thread, it's in the weave.
The three gestures: Capture · Connect · Create
Itomori boils everything down to three gestures, so the method never weighs more than the tool.
- Capture. You drop in a thought — by voice, with an audio file or in writing — without deciding right away where it goes. Voice is the most natural way: you talk for 60-90 seconds and Itomori transcribes it in your language, keeping the raw text as the source of truth.
- Connect. The AI structures the note and links it by meaning to the others. Not through hand-picked tags, but by sense: semantic search, related notes, and the ability to “ask” your archive and get answers drawn from your own ideas.
- Create. From one note — or a cluster of notes — you generate something publishable: a post, an email, a speech, a summary. This is the moment the second brain stops being a warehouse and becomes a workshop.
What a second brain is not
It's not another to-do app. It's not a library of PDFs you'll never read. And it's not a system of folders ten levels deep: rigid hierarchies age badly, because a thought often belongs in several places at once. Better a network that forms on its own than a tree you have to prune by hand.
Why your own language changes everything
Most tools think, transcribe and “reason” in English. If your thoughts are in another language, a tool that puts your language first better understands nuances, idioms, double meanings and context — from the quality of the voice transcription to search by meaning, all the way to the content it generates. Language isn't a detail: it's the material you think with.
And then there's privacy. Your thoughts are intimate data: with Itomori they stay in the EU, under the GDPR. A second brain must, above all, be a place you trust.
An example: three notes that talk to each other
Imagine capturing, in different weeks, three unrelated thoughts. On Monday, by voice: “it strikes me how in Japanese design emptiness isn't a lack, but a choice”. Two weeks later, a note from a call: “the client says the competitor's app is too cluttered, they feel overwhelmed”. A month later, in passing: “maybe our strength is taking away, not adding”.
On their own, three forgettable fragments. But when you write the third note, a second brain puts them in front of you, connected: emptiness as a choice, the overwhelmed client, taking away as a strength. At that moment you no longer have three notes — you have a thesis, almost a product manifesto, born from the crossing of distant thoughts you would never have linked from memory. This is the moment the system “gives back” more than you put in.
How to get started in 5 minutes
You don't need an elaborate system: you need to bring friction down to the minimum and repeat it a few times. A concrete start:
- Your next thought: record it instead of writing it.
- Let it be transcribed and connected on its own — don't tidy it up right away.
- After a few notes, open the connections and see what has linked to what.
- When you need it, turn a note into content: you'll see the value “come out”.
Within a couple of weeks you'll have a network that surprises you. You can see it at work on the Product page, or read how to turn voice notes into text and then into content.