Your Second Brain Doesn't Need Another App. It Needs Four Folders and a 15-Minute Friday

Sort by what you can do with it

Actionability is an easier question than topic, and it has only four answers. Four folders, numbered so they sort hottest to coldest:

• 1-Projects/ - what am I actively doing? It has a deadline or a defined finish: "Launch portfolio site", "File taxes 2026".
• 2-Areas/ - what do I maintain with no end date? Health, Finances, Career, Home, Learning. Nobody finishes Finances.
• 3-Resources/ - what might be useful later, filed by topic because the topic is the retrieval cue? Code snippets, recipe notes, design inspiration.
• 4-Archive/ - finished or inactive. Cold storage, not the trash.

One rule holds it together: every item lives in exactly one folder, and one question decides which: what does this help me do?

That question resolves the kitchen case in four seconds. A renovation you have started goes to 1-Projects/Kitchen-Renovation. An article about layouts not tied to any project you are actually running goes to 3-Resources/Home. Last year's notes from a project you abandoned go to 4-Archive/2025/Kitchen-Renovation. Same subject, three homes, and the deciding factor was never the subject.

Two tie-breakers for when the question is genuinely unclear. A deadline and a checkable finish make it a Project. Nothing I would act on inside a month makes it a Resource. Still stuck? Archive it. Pulling a file back out takes two seconds; relitigating a filing decision takes two minutes, and that is why people stop capturing.

The inbox is not optional

One file catches everything first. Mine is INBOX.md, and its instructions are two lines: everything lands here, sort it once a day, and do not organize while you are capturing.

That last part matters more than it sounds. Once capture requires a folder decision, capture starts getting deferred, and a deferred capture becomes the note you wrote on your hand about a deadline. The inbox buys speed now and pushes the decision to a moment when you have spare attention. Sorting takes a minute: file into 1, 2, or 3, or delete. Delete is a legitimate answer for most of what lands there.

Projects earn a file by defining "done"

Every new project starts from one template, and the template is mostly a gate:

• Project name, the area it serves, and a deadline or the honest word "none"
• Goal: one sentence on what success looks like
• Done when: two or three concrete, checkable conditions
• Next actions: only the next one to three, each starting with a verb, e.g. "Draft the homepage outline", not "homepage"
• Notes and links: paste freely, sort later

The "done when" section is the piece that changes behavior. "Work on the portfolio" has no finish, so it can never be completed, so it sits in the Projects folder for eleven months making you feel behind. "Live on my own domain with four case studies" is something you can either do or stop doing, and once the boxes are ticked the file moves on its own at the next review. Verbs in the next-actions list do the same work: a noun there is a category, a verb is something you can do Tuesday at 9am.

The 15-minute Friday is the actual product

Most systems, including paid ones, skip maintenance. They hand you folders and a philosophy, and three weeks later the folders are wrong because the projects inside them are wrong, and nobody told the folders. A second brain dies of a stale taxonomy, not of bad structure.

So the file ships as a checklist, WEEKLY-REVIEW.md, and the point is that it is fifteen minutes rather than a ritual. My timing on it: five, five, three, two.

1. Empty the inbox (5 min). Every item filed or deleted. Then a quick sweep of the phone camera roll, the downloads folder, and the email where you sent something to yourself "so I remember it". Strays are where trust goes to die.
2. Reconfirm projects (5 min). Walk every file in 1-Projects/. Active and wanted this month? Done or dead ones move to 4-Archive/YYYY/. Check that each survivor still has a written next action.
3. Check areas (3 min). Look for an area quietly going wrong that needs a new project. This is where the system earns its keep: Finances looks fine as a folder until you notice the parking ticket you have ignored for six weeks, which becomes 1-Projects/Unpaid parking ticket with a done-when of paid or contested in writing.
4. Pick the week (2 min). Choose next week's top three projects and write them in the file. Then fill in the date of your last review at the bottom.

That last line is the cheapest accountability trick in the system. An empty date field is visible, and it drags me into the review more reliably than any intention I have ever set.

Plain text is why it survives a switch

Everything above is folders and markdown files, so nothing depends on a plugin or a vendor account. If the app gets worse or the pricing changes, you copy the folder into the next thing and it is already organized, because the structure lives in the directory names. Obsidian is free and its search makes the folders more useful, so it is what I reach for first. In Notion the same four folders become four pages with the same files pasted in. Either way, the method never needed a new app.

The 30-second version

1. Four folders by actionability: Projects, Areas, Resources, Archive.
2. One question decides placement: what does this help me do? Still unsure, archive it.
3. One inbox file, sorted daily, never organized during capture.
4. Projects need a checkable "done when" and verb-first next actions, or they do not get a file.
5. Friday, 15 minutes: empty the inbox, reconfirm projects, check areas, pick the top three, write the date.
6. Plain markdown, so moving apps later is a copy-paste and not a rewrite.