ADHDSet Up a Second Brain in Obsidian, Step by Step (and Turn On the Map)
This is the companion post to the four-folder argument. That one told you why Obsidian with four folders beats fifty plugins. This one is the actual walkthrough — every click, in order, from "I downloaded a thing" to the moment your notes appear as a living map of your own mind. Twenty minutes, zero dollars, and you don't need to be technical. If you can make a folder on a computer, you're qualified.
Before we start, the honest frame: a second brain doesn't treat ADHD, and neither does any app in this post. What it does is simpler — it gives the hundred crumpled papers in your mental backpack somewhere to live outside your head. That's it. That's plenty.
Step 1 — Download Obsidian and make a vault (5 minutes)
Go to obsidian.md and download the app for your computer — Mac and Windows both work, and it's free for personal use with no trial clock. There's a free phone app too, but do the setup on a computer first; the bigger screen makes the first day easier.
When you open Obsidian, it asks you to create a vault. A vault is just a folder on your computer where all your notes will live — that's the entire concept. Click Create new vault, name it something you'll actually like seeing every day ("Second Brain" is fine; so is "The Backpack"), pick where it lives on your computer, and click Create. If the app offers you themes, plugins, or sync — skip everything. We're using it stupid-simple on purpose. The complexity everyone warns you about only shows up if you go looking for it.
Step 2 — Make exactly four folders (2 minutes)
In the left sidebar, right-click and choose New folder. Make these four, and no fifth one, even if you can already think of a good reason:
Inbox — where every thought lands first, unsorted. Projects — things with a finish line. Areas — ongoing life stuff with no finish line: health, money, family. Resources — things you look up later. If you want the full reasoning for each, it's here. The one rule that matters today: when in doubt, it goes in Inbox. Sorting is a different job than capturing, and you never do both at once.
Step 3 — Your first yap (3 minutes)
Click the Inbox folder, make a new note (the pencil-and-paper icon, or Ctrl+N on Windows, Cmd+N on Mac), and title it today's date. Now talk — phone dictation into the note works great, and typing messy works too. Sixty seconds, no editing, no organizing while it comes out. Everything on your mind: the bill, the call you're dreading, the idea from the shower. Done? You now have a second brain with one note in it. It already holds something your first brain was carrying alone five minutes ago.
Step 4 — The two square brackets (this is the magic part)
Here's the feature that makes Obsidian different from a pile of sticky notes. Somewhere in that first yap, there's a noun that deserves its own note — a project, a person, a worry that keeps coming back. Put your cursor next to it and type two square brackets, then its name:
[[Storage unit cleanout]]
The moment you close the brackets, that text becomes a link. Click it and Obsidian creates the note it points to. You didn't file anything, you didn't build a system — you just typed brackets around an idea, and now your daily yap and your project are connected. Do this every time a note mentions something that matters: [[Health]], [[Mom]], [[The court case]]. Two or three links per note is plenty. This tiny habit is the whole trick, and it costs you four keystrokes.
Step 5 — Turn on the map
Now the payoff. Find the graph view icon in the left ribbon — it looks like connected dots — or press Ctrl+G (Windows) / Cmd+G (Mac). Obsidian draws every note as a dot and every bracket-link as a line between them.
Day one, yours will be two dots and a line. That's not a sad little graph — that's a seed. Every daily yap adds a dot. Every pair of brackets adds a thread. Nobody plans the shape; it grows out of the habit, the way a garden grows out of watering.
Day 1 vs. week 8
Same habit, same brackets — just repeated
Your notes stop being a pile and start being a place.
We built a live, clickable map of a demo vault so you can feel this before you've earned it: eight weeks of one person's daily yaps, thirty-two notes, forty-four links. Drag the dots around. Click a note and follow its threads. Then press "Grow it" and watch the whole thing happen week by week. Day one looks small. Week eight looks like a mind.
Step 6 — Let AI do the filing
Obsidian doesn't have AI built in, and for our purposes that's a feature — your notes stay on your machine, nobody's servers involved. The AI lives next to the vault: when a yap is too tangled to file, copy it into any free AI app and ask it to MAP this into five piles: Tasks, Worries, Ideas, Feelings, Questions. The piles tell you what deserves brackets and which folder each piece belongs in. Paste the sorted result back into your note, add the brackets, done.
The standing rule when anything leaves the vault for an AI chat: the postcard rule. Fake names, no medical, legal, or money details. Your vault is private. The chat window isn't.
The habit that keeps it alive
Two commitments, both tiny. Daily: one sixty-second yap into Inbox, brackets around anything that matters. Weekly: ten minutes on Sunday to skim the Inbox and move what's ripe into Projects, Areas, or Resources. Delete nothing, reorganize nothing else. The vault is an inbox, not a museum, and most notes can just sit there being remembered for you.
And that's genuinely the whole setup. No plugins, no themes, no $20-a-month tier waiting to ambush you — the price stays zero. If you want sync to your phone later, Obsidian sells an official sync service, but you don't need it to start, and because your notes are plain files in a normal folder, free routes work too. Start with the computer, the four folders, and the brackets. In eight weeks, open the graph view and meet your own constellation.
Take the whole system with you
The free 43-page ebook: the brain science in plain words, the four steps, the master prompt, and your first seven days.
Prefer it live? Doug teaches this exact setup in Build a Second Brain — book a 90-minute class →