Do you really need a "second brain"?

I’ve just realized that I’m 53 and I’ve been quite successful (so far) by using my first brain.

Am I alone?


I don’t think so, but I don’t claim to know what a “second brain” really is. How many people actually refer back to the things/information that they create? Some do, but I imagine most don’t.

I’ve never been great at keeping track of some things, and increasingly over the years I’ve found myself rediscovering things I previously had figured out. And I have ideas for accomplishing things that I’m not going to get to in the immediate future.

A big old file full of plain text notes helps me store the things I can’t be bothered keeping track of in my first brain (who was the arborist I hired three years ago, and what did I have them do?), or that probably aren’t going to stick but may still be useful later. And when I do decide to tackle that project, it’s great to have close at hand the material I’ve already put together.

Do you need it? Hell if I know. I find it useful.


Good point - though when I think of “second brain” I’m thinking of the carefully curated, linking your thinking, zettlecasten, PARA sorta systems, which are (I think) different to having archives.

I could easily track down the gardeners we used 5 years ago by searching in my Gmail, or my contacts, or Google, without needing any [[backlinks]].


My secretary is my second brain. Couldn’t manage without her!


I used to be 53 and I’ve always relied on a “second brain”. My first SB was a legal pad, and some 3x5 cards. My second was a franklin planner, and some 3x5 cards.

My current version is a Google Workspace account, a Due app, and some 3x5 cards. They all work about the same but my new one is harder to lose. :grinning:

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I believe David Allen is right when he says “Your mind is for having ideas, not holding them.”

I’m in that 50s zone where doctors recommend I get a colonoscopy every five years. So I have a note that keeps track of the last time I had one and a reminder in Things to get another one five years after that. Why would I want to try and remember these things without the aid of a second brain?


Yep, the good old days!

I’ve looked into PKM and second brains a little (meaning I’ve watch copious YouTube videos). I tend to think I can manage without the structure. Yes there will be times of stress of knowing where something is but, from what I have gleaned, a SB doesn’t eliminate the stress.

I think, for me, the “trusted system”, as per David Allen, is my SB, of sorts.

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I think it depends on what you note and how you use it, or intend to use it. I wouldn’t call it a second brain, but because of what I do—I’m an academic by training, specializing in early English and Celtic literatures, but make a living as a tech writer—I’ve always had notes about references.

Even if I don’t know what project/book/article/class specifically a note will be used for, I create reading notes with detailed commentary and links. Most of the links are either to supporting references on the Web in general, or direct links to my local data set, possibly another note, or subheading of a note, or tracking a theme.

Usually, when I start accumulating a set to write something, I generally want my notes in hard copy. I realize that this is odd, particularly given that for long pieces I draft in Scrivener, but I really like to fondle my data.

“Second brain” overstates my position in life. “Second half of brain” would be more accurate.

My understanding of the term is simply to capture information so it can be recalled reliably. Not really a second brain but a second memory. A true second brain would take the question written down and offer you the answer when you need it.


Many times I’ve had to refer back to meeting notes, things saved from the web or daily notes. I doubt the repercussions would have been massive if I hadn’t been able to do so, but it’s certainly been more than useful.


As others have already acknowledged, this depends in part on definitions of “second brain” and “need”.

I don’t think there’s anything wrong with taking many more notes than you ever refer back to; there can be value in taking notes even if you never refer to them again— offloading troubling thoughts or processing ideas.

I take notes all the time and refer to them regularly. My daily notes are useful for maintaining state and tracking progress; other informational notes are useful for recalling details I’d otherwise lose track of, following up on threads from conversations or meetings, drawing on research or as-yet-undeveloped ideas for new writing, etc etc ad infinitum.

Also, I consider my “second brain” to be my entire set-up for action and information management: tasks, projects, events, notes etc.

Could I function without all this? I’d like to think so. But given the fact(s) that a) it’d likely be much more painful to do so, b) I’d probably end up deciding some other (paper-based?) system to provide some similar function even if less efficiently c) I have no idea whether I’d be able to produce the same quality of outputs without the systems I’ve put in place or some equivalents… I’d be willing to define these systems as “needed” for me. :slight_smile:


I wouldn’t go as far as calling any system I could devise a “second brain”. However, I strongly believe that these systems can be used to assist my brain to great effect. Like a bicycle for the mind, as it were.


Regarding linked notes.

The processes involved in making notes, revising them, and making links with existing notes mimics how our own brains work. The consolidation process for our brain occurs mainly when we sleep, and may be the source of imagery when we dream. Interestingly, this occurs for “motor” learning as well, such as the next time you sleep after playing a game of tennis. Your movements are refined and adjusted so the next time you play, you’ll be slightly better.

The revision and link process in note taking also exposes us to the information multiple times, and helps ensure we actually think about it (unlike, say, highlighting). We put things into our own words. Our brains are quite adept at fooling us by filling in the blanks between what we actually know. We don’t discover this until we are required to use that information (such as on an exam, or in a meeting). This is where the Feynman Technique is useful. This helps in combatting familiarity bias, where you reread the same text and “feel” like you’ve got it, but then can’t reproduce the information.

The process of building this “second brain” also helps our first brain understand and retain the information.

In days of yore, people did a similar process using a “common place” book. They might have access to a text for a limited amount of time, so distilled down what was important and salient and wrote it in their common place book.

Edit: This video by Morgan is a nice summary of a note taking process.

Edit 2: This article about sleep and memory retention just came up in my Twitter feed.


Wait’ll you’re seventy :slightly_smiling_face: (age varies by person). I often use my Mac or my phone to try to look up a word or a name that I would like to remember using a scrap of something that I do remember. Feels like a second brain to me.


I think the term “second brain” referring to note is missing things. Do we all have an address book? Calendars full of appointments and anniversary’s/birthdays? We all have limits to what we can hold on to. We all need something, I varied formats, to help us live the best life we can.

Yes, I have embraced the second brain for my note and am starting to distill thoughts, books and articles to something smaller. This helps me in work and life.

I’m 52, and was diagnosed with ADHD in March of 2020. This discovery has help me understand I can not and should not try to keep holding things in my head. It exhausting and there are better ways, for me that’s Obsidian.


Welcome to the club! I was unofficially diagnosed long ago, but officially diagnosed a year ago. Medicine helps so much! The best book on ADHD I’ve read to date is ADHD Pro by Robert Merki; it is very actionable.

Cue a reference to David Chalmers, and his development of the idea of the extended mind, where objects external to us become part of our thinking processes.

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Along those same lines, isn’t any technology a “second brain”? Technology is congealed thought, in a way, and all of that congealed thought has allowed us to progress, instead of having to keep thinking the same thoughts over and over again in order to accomplish anything.

To oversimplify it (and to purposely refer to “technology” as something beyond what Apple, Samsung, or Google might make): The person who invented, say, the cup — as a technology for drinking liquids — solved a problem. Every cup ever made since then is an expression of that original solution, so that each one of us doesn’t have to keep inventing a way of carrying around a drinkable liquid and occasionally sipping some of it every time we want to do that.

Further, the means of recording the instructions for making a cup, so that others can learn how to make cups instead of having to keep inventing their own version over and over again, is also a technology that serves as a second brain, whether that’s cup-making instructions carved on a rock, published in book, or composed into a file that can be rendered by a web browser.

In other words (and I think to echo somewhat @Clarke_Ching’s original intent with this topic), “second brain” may be a catchy marketing term, but the concept ain’t exactly novel.

The “second brain” thing is a not-too-clever marking trope. It will eventually go away.

What saddens me, is reading desperate posts on various forums, Reddit, etc., where someone posts something like: “You guys recommended it, so I got Obsidian for my ‘second brain’, and I’ve been writing down every thought I have. I have 2,500 notes now, and I’m really struggling to make my graph look like the ones I saw on Discord. How do I link all my thoughts?”

I just want to say “dude, chill … take a breath … don’t try so hard … step back”.



This thread reminds me of the seminal “As We May Think” essay by Vannevar Bush in 1945, expressing concepts that were later encapsulated by Steve Jobs in his now famous 1990 interview where he coined the phrase “bicycle for the mind”. Although decades apart both envision computational systems that expand and enhance natural abilities, the same concept now being used to market fancy note-taking apps.

I’d say what you need out of your computer is very personal, and how you choose to organize your information is best left up to you. The unique recipe of apps and workflows you’ve come up with over the years reflect the inner workings of your mind, and how it chooses to express a logical system to organize and retrieve information. So, if you’ve been working with computers for several years (or decades), you’ve most likely already found a system that works for you, so adding an additional layer of complexity through linking notes might not be valuable to you. However, if you are the kind of person that enjoys organizing things and spending lots of time reviewing previously captured information I can see how something like Obsidian, Notion, or Craft would appeal to you.

Everyone needs something different from their computer. For me, I want information capture and retrieval to be as effortless as possible. I hardly ever review previous notes, but I do search for information frequently. Where’s the receipt for these doors? What was that code snippet for deploying a CloudFormation template? What did I buy my niece for Christmas last year? Where did we leave this long-running project?

I’d say the question you are asking isn’t really about having a “second brain”, but about adopting an application and workflow that you see dubious value in. The real second brain is the entire computer.