Most advice about AI and company documents is about a single moment: should I paste this contract into a chat? A second brain raises the stakes slightly. You are not pasting something once. You are storing it somewhere your AI tools will read again and again, across tools and over months.
That makes the decision worth taking deliberately, once, rather than at four o’clock on a Thursday with a deadline in front of you. The good news is that most of what a useful second brain needs is the easy kind.
Question one: which account is it going into?
The account matters more than the tool. The terms that govern your material differ between personal and business plans, and they change, so nobody’s summary of them - including this one - is a substitute for reading the terms for the exact plan your organisation pays for.
Do that once and write it down: whether your inputs are used for training, how long material is kept, and who can access it. Copy the actual sentences, with the date you read them. It takes ten minutes and settles most of the argument.
The rule that follows is simple. Work material goes into the work account your organisation has approved. Never a personal one, however convenient.
Question two: what kind of information is it?
Sort anything you might add into four groups.
- Public. Already published or publishable: your website, public prices, articles, industry material. No restriction.
- Internal, not personal. Your own drafts and notes, how you write, what good looks like, decisions and the reasons for them, the recurring facts of the business. Fine on an approved account.
- Confidential or personal. Named customers, anything about identifiable people, salaries, unreleased figures. Redact it, or get an explicit decision before it goes in.
- Regulated or contractually fenced. Health data, payment details, national identifiers, anything a law or a contract says how to handle. Not without a written decision from whoever owns that risk.
The second group is where almost all the value of a second brain sits, and it is the group people wrongly treat as forbidden. The five kinds of context worth storing are overwhelmingly internal and not personal: your voice, your standards and your reasoning, none of which is anyone else’s personal data.
Question three: whose information is it?
A document from a client is governed by your agreement with that client, not by your AI plan. An enterprise plan can answer the question of how the provider treats your data and still leave this one open. If a client’s material is under a confidentiality clause, the clause decides, and “I put it in my second brain” is rarely something it anticipated.
The practical answer is usually to store the lesson rather than the document. What you learned about how that client works, written in your own words and without identifying detail, is often more useful to your AI tools than the original document would have been.
Two habits that carry most of the load
Scope access narrowly. When a tool connects to your files or drive, grant it the folder your second brain lives in, not everything you have. A connector reading your whole drive will find things you forgot were there.
Keep credentials out, always. Passwords, keys and access codes do not go in a second brain in any form, on any account. There is no version of that which is worth the risk.
Where this gets practical
The Oxford Second Brain Bootcamp is built from your own material, so it is worth running this sort before you arrive and bringing what passes it. The day is spent turning that material into a second brain your AI tools can draw on, organised so it stays findable and set up to maintain. Cohort 1 ran on 21 October at the Pitt Rivers Museum, and dates for the next cohort are being confirmed. No coding required.