Do you really need a "second brain"?

Me, all the time. as @tf2 says it’s all the things and ideas and notes.

I guess I disagree that those are “carefully curated” that may be the ideal but is sure as heck isn’t the reality of people actually using those systems vs those trying to sell you on the concept. The sellers have carefully crafted incarnations that look beautiful but may not work in practice. It’s up tot eh user to figure out what works.

I might be able to find that info by searching but I can find it faster with less angst by refering to my note on gardens where I linked in the name of the person and what they suggested we do about some large trees sometime in the next 3-5 years.

Me too. My first was spiral bound notebook with divided sections, once for each class and one or 2 for my personal ideas and fun stuff. I typically had 2 or 3 of the 5 or 7 sectionnotebooks at any given time so ech area was somewhat separated. I added a paper calendar to that. Then Covey style planners, DayTimers, 3x5 cards ala Slob Sisters, paper checklists laminated so I could wipe them off and reuse them and more. Now it’s Obsidian, Omnifocus, Apple Mail, Apple Calendar and an extensive paper and digital filing cabinet structure. The current version is much easier to use and locate stuff in compared to the old one and I’m slowly scanning and making digital all the paper I can.

My Obsidian vault is called my Adversaria as a nod to the commonplace book.

You could argue that pretty much all of civilization, writing, story telling, pretty mcuh everything external to us is a second brain of sorts.

And in some ways that came out of Heinlein’s “Beyond This Horizon” originally published in 1942 under one of his pseudonyms.


Isn’t this the evolutionary function of grandmothers? :wink:

In all seriousness, zookeepers have discovered that primate new mothers need an older female around to teach them how to deal with their squalling newborns.

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I would for one would be happy with a better first brain. :grinning:


You have put your finger on the nub of the problem!

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Due to my ADHD, I nearly forgot to reply to you @Clarke_Ching :slight_smile:

I’m using the approach to help me pay better attention things I already know and spot connections between things that I hadn’t previously noticed.

Last week I attended a virtual talk by Danny Hatcher: Homepage - Danny Hatcher and wow, the breadth and depth of his notetaking blew me away.

Trivial example Dunning Kruger got mentioned, I pointed out via the chat that its been demonstrated to a statistical misreading. Then I found his notes, which were clearer and better expressed than my thoughts.

So I don’t know if anyone else needs it, I know I’m having fun getting back at my tradecraft.

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I am with you, I found at one point that ‘productivity’ was actually slowing me down. I have to declare that I would not, without evidence extend that to other professions. My wife for example needs a high degree of access to diverse stuff; she does it in her own head though. In a way I never could, maybe were I taking a lot of clients or something I might think differently.
I hardly take notes either and come from an earlier epoch I guess? I use DEVONthink 3 and am a big fan though, without being able to tell you exactly why it works for me, something like the old journal, paper piles we used to have where one ‘knows’ where everything is? I love it and do all my work in it.

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Here is the value of the links, you might a connection between something you learned on Focused and the Theory of Constraints,

It’s been difficult for me to see PKMs as a second brain. Because my brain is, above all, a processor. It can compute things. PKMs don’t process anything. What I’ve landed on is that a PKM is a second hard drive. Anything I offload to it, I can remove from my brain’s RAM or ROM. I can properly quit that app until I need it, instead of keeping too many apps open on my mind’s desktop or even minimized in my mind’s dock. And that does help me work and think clearer.


It’s funny you should write that @mlevison because almost every time I listen to Focused I do think of ToC and Agile.

I can’t help but think about how the thinking and tools (that work well) for personal productivity need to be tweaked when scaled up to be used by teams.

I imagine you have similar thoughts, Mark.

Are we debating the utility of cognitive extensions/prosthetics, or critiquing an imprecise metaphor and branded system for managing information?

A short series of observations, summary points and opinions, some of which may be hilariously obvious, some of which might spark further conversation. Please feel free to suggest edits/push-backs…

  • Getting some things out of your own brain and into a trusted system (e.g. information storage and retrieval) can be useful.
  • Some people struggle with organisational architecture for their information, hence the interest in (and potential value of) systems like BASB, LYT, zettelkasten etc.
  • Even if you don’t follow such systems to the letter, they can provide a set of principles you can adopt or reject in service of your own bespoke system.
  • Even if you evaluate a system and decide it doesn’t work for you, understanding why can be a useful datapoint.
  • The value of these systems is subjective and variable.
  • Different people can approach the same system or tool with different needs, and so their evaluation of a system can arrive at completely different conclusions about that system’s utility or value.
  • Backlinks are neither a universal good nor empty of utility. Backlinks are also not a characteristic feature of a second brain system.
  • It’s easy to conflate systems and tools, to the extent that one can be cynical about a tool on the basis of what one thinks about a system (and vice versa?)
  • None of these systems do the work for you, and even as artificial intelligence is wired into tools to make it easier to categorise or link discrete informational units, or zero in on the most appropriate information in response to a query, the user will still need to put at least some effort in to derive meaningful outputs.
  • We sometimes make assumptions about what “the work” actually requires— whether that’s retrieving a phone number at the most opportune moment, or figuring out how to increase the likelihood/efficiency of generating novel insights.
  • It’s easy to fall for the hype about a new system or tool and then be disappointed when the expectations aren’t fulfilled.
  • Some of these systems/tools take more work to meaningfully implement than we account for.
  • The more prevalent artificial intelligence becomes in “second brain” systems, the more likely we’ll each need to interrogate (for ourselves) what “the work” actually is.

Personal note: I’ve tried to get into DevonThink many times over the past 5-7 years. Part of the appeal was the artificial intelligence it offered. But after several attempts, I never did manage to make it work for me. That’s no criticism of the DevonThink, just an acknowledgement of my own needs and preferences. As it currently stands, the core of my note-taking system is Drafts (a relatively “dumb” tool by comparison, by which I mean no AI), which I use with wiki-links, a custom syntax, some actions for block-level thinking within notes and other affordances that have thus far met my needs perfectly. What I thought I wanted/needed is not what ended up providing me most value.


I would say, above all your brain is an associator. Our memories are associative. If we know five things that are associated with one another, and one thing happens to be missing in a given situation, we can recall that fifth associated item.

Linked note taking mimics creating and refining these associations, and thus helps our thinking and recall.


Others including @jsamlarose have been far more articulate.

I will add some minor colour. Danny Hatcher gave one of the more interesting talks at the second LYT conference last week on Extended Cognition: Extended Cognition - Danny Hatcher this seems like a better metaphor than a second brain. His notes database is an amazing example of how it might be used well.

How I’m currently using PKM - I have a topic I write some notes on. I put them in Obsidian and link them to anything related that comes to mind. Next time the topic comes up, I refine the notes, add more reference sources and perhaps new links if they occur to me. Rinse and repeat.

My PKM includes notes on technology, running a small business and many things related to making workplaces more effective. I even have notes for my favourite rants. (Please never say Learning Styles when I’m around).

I dislike the metaphor and like the tooling. FWIW I will shock some, I read Tiago’s book and was left cold. It felt like a sales pitch for his course. 1/3 sizzle and almost no steak.


To slightly modify something @MacSparky said on one of the podcasts recently, my understanding is that the mind is a great processor, and can be excellent storage (long term memory, or think of actors learning lines every week for TV shows), but has fairly poor RAM (to use computational analogy which is probably the wrong one anyway). I think it’s the long term storage that many of us forget the brain is good for, something Nicholas Carr pointed out in The Shallows. All this to say, I’m sure there are still some benefits to ‘building a second brain’ with 3x5s, a notebook or a full-on software solution, but to not forget the power of the first brain, as the OP might be reminding us to.

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I can see this thread has wandered around the topic a lot; perhaps a much tighter question was needed :grimacing: I’m guessing 90% of the world (BOLD CLAIM) probably scribble notes, take photos or do any number of little things to remember tasks, useful bits of info, etc. They’re all “aide-mémoires”, but probably not what Silicon Valley would have us believe are “second brains”. I’m guessing OP does this too, even if they don’t recognise it as a supplement to “the original brain”.

[Technically we actually have 3 different brains and only your human brain is doing this sort of thinking - your reptilian brain and mammalian brain have other stuff to do. The new brain functions evolved on top of the previous set of functions, so as an amusing detour technology should really be our “Fifth brain” if we count the development of pen and paper as the “Fourth brain”.] My brain has now melted with this daft detour.

I have very non-techy friends who have iPhone photo albums running to thousands with all sorts of random shots of things they need to remember, and many writers have written about the beauty and uniqueness of the notes people write to themselves in Apple Notes.

I don’t buy into the hype that this is some new development - the tools have changed but people have done this sort of stuff for millennia. It’s what writing was invented for!

I use DevonThink and keep tinkering about in Obsidian (I consider this secondary to DevonThink though). I rarely backlink because life is short and I don’t care. I use folders and search, and expect my brain to do the actual thinking. I see some people make exceptionally bold claims about what “second brains” can do, but at the end of the day the person at the keyboard is the one who has to do the thinking, and if they aren’t then what are they doing (if an app can do this work for you, you’ve either just done yourself out of a job or you should automate that part of your life and go do something fun!).

I’ve written notes and “saved” important things all my life (avocado-eating millennial here). I don’t really use the apps any differently to how I used actual paper notebooks, they just make this all a heck of a lot easier, and you don’t have to worry about needing a second house for your library.

Some of this will depend on your personality, trade and hobbies though. I read a lot and am a knowledge worker, so I do need (and like) to remember stuff. When I was a student working in a shop, I rarely had to remember or know stuff that wasn’t already in my head, and probably wouldn’t have a need to write lots of notes on things. (Although as others have pointed out modern life involves a lot of administration and most people have probably implemented some sort of system for dealing with it, even if it’s not very efficient!)

In conclusion, “second brain” is a daft term but an easy one for referring to all the systems we have that prop up our thinking.

I was eating a free sample of a new snack while I wrote that, and I just took a photo of the packaging so I can find it again because it was tasty. Second brain in action!


For this reason, my second brain is my system(s) for building and navigating my various information repositories, not the repositories themselves.

“Systems” because not all repositories are alike, because some stand alone, and because some need to be used in conjunction with one another.

PS: Yes, I need one.

I think everyone is different. I’m pretty sure everyone keeps information in a system outside their mind to some degree (my 83 year old mother keeps a notebook and calendar). But I have to say for me, at least (as a 55 year old) that while I’ve been ‘successful’ without a PKM tool like Obsidian, I’ve been using it for about a year and I’m finding that it really does make a difference. When planning a presentation, for example, it helps me to think of relevant stories or examples I’d collected and I’d forgotten all about that that I can bring in to the mix. I had all those things as notes before, but they weren’t linked. But moving them into Obsidian has meant that they are surfaced at appropriate times. I do have to say though that it takes a while, and a lot of consistency to get the system to a point where the benefits start to become apparent - for me, anyway. I gave up on it a few times before finally I started to see the benefits. Was it worth the effort? debatable. Am I glad (now) that I moved everything over - yes.


Me too, I’ve still got a few lingering things in my old systems. After pulling into Obsidian all the top level and most important stuff I’m slowing down and moving things in from other sources as I need them. When I did the major conversion I refactored a lot of notes. Some long ones became multiple notes in Obsidian, some short ones were near duplicates and got combined. I also trashed a lot of old extraneous stuff.

End result is a much more useful archive and annotation system. At least for me it is.

Another thought, when I am looking for something I think shuld be in my Obsidian system, and if it isn’t I add it. If it is in there but not where I first looked I create a link to it in the first location. Over time it means I can go directly to the place in obsidian where the info I need is located without resorting to search.

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Yes - it takes time, practice, and, most important, thoughtful planning and revision.