I first started taking notes on a computer at the age of 22, when I came down with a mysterious illness in college. The pain was inconsistent, varying a lot from day to day. At first I thought it was a temporary thing, that it would soon go away. But it grew steadily worse, over months and then years. I started seeing every kind of doctor and specialist I could find. But none of them could pin down the cause, much less a solution.

I found myself sitting in a neurologist’s office one day, as the doctor recommended a powerful painkiller that might fix the problem at the cost of dulling sensation throughout my entire body. Considering such a drastic measure, I realized that I was at rock bottom. I felt like I had no future, that the things I wanted in my life were permanently out of reach because of this condition I couldn’t explain. Sitting in that chair and watching the doctor write the prescription, I had a realization: I could spend years bouncing back and forth between different specialists, taking various medications, and never find true relief. I realized that no one person was going to solve this problem for me. I had to be my own advocate. I had to take charge of my own treatment.

I began asking the receptionists for my patient records and scanning them into my computer. Before long I had an extensive file to manage, and I started organizing it by date, by specialty, and by doctor. I would arrive at each doctor’s appointment with a list of questions I wanted answered by the time I left. I started doing my own research, reading about obscure findings in medical journals, and guiding the process according to what I thought might help.

Eventually, it became clear that there wouldn’t be a definitive remedy. After every diagnostic test and scan imaginable, and tens of thousands of dollars spent, there didn’t seem to be any single cause for my symptoms. I began to realize that what I had was not a temporary illness, but a chronic condition. I needed to manage it, not fix it. My notes again came in handy: in a matter of hours, I was able to search through years of observations and findings, tagging anything that seemed to help. I was able to identify almost a dozen practical measures – for sleeping, eating, exercising, and stretching – that when practiced regularly, helped minimize the pain and allowed me to function normally. It seemed like a miracle, but the answers I needed were waiting right there in my notes.

Speaking with people about my experience over the years, I’ve been surprised to find that many of them have some sort of chronic condition. A bad knee, a mysterious allergy, a recurring infection, or an addiction that they can’t kick no matter how hard they try. The medical system isn’t designed to treat us holistically. If it can’t be fixed with a pill or a surgery, it falls on you to organize your records and change things up when they’re not working. It was around this time that I began to seriously think about the potential of digital notes to improve people’s health, whether they are sick or just need better self-care. What if instead of a patient chart with indecipherable scribbles only available to doctors, we had an organized and accessible database of our entire health history across every doctor?


I returned from the Peace Corps in 2012 and moved to San Francisco, plunging directly into the epicenter of Silicon Valley for my first “real” job at a boutique consulting firm. The transition was a total shock: the pace of work and the volume of information I was expected to handle were utterly overwhelming.

In an effort to keep my head above water, and to document the immense amount of learning I was expected to take on, I again turned to digital notes. I began writing down everything I learned, from facts gleaned from research reports, to interesting insights I saw on social media, to feedback from my more experienced colleagues. As time passed, this repository of notes became a valuable tool in delivering my work quickly and at high quality. My colleagues commented that I seemed to have an incredible memory. But I wasn’t remembering at all. I was retrieving things from my notes. I became the go-to person for finding that one file, or retrieving that one fact, or remembering exactly what the client said.

I learned a lot in that job about how knowledge is acquired and sold. The consultancy is essentially being paid by their clients to learn about cutting-edge new trends, such as machine learning, big data, gamification, online marketplaces, or chatbots. This learning is inevitably time-consuming and messy, but once the analysts have been through that difficult learning process, the company can turn around and convert that knowledge into all kinds of other formats like workshops, talks, panels, conferences, social media posts, and white papers. I began to see my growing collection of notes not just as a professional asset for a single job, but as potentially a business asset I could one day use to start a business of my own.

As much as I enjoyed the experience that consulting gave me, I was getting tired of the relentless work schedule required. I had no desire to climb the corporate ladder, only to take on an even more demanding schedule. I knew that I had something to offer from what I had learned and experienced in my life. I had always been a teacher – of English as a second language and computer skills. But I wanted to contribute my own ideas directly to people who could benefit from them. I wanted to take control of my destiny, but wasn’t quite sure how.

I discovered online courses in 2013, and quickly fell in love with the idea of teaching people all over the world what I knew. I decided to make one of my own, and once again, my digital notes came to the rescue. I found that my habit of writing everything down in one place meant that my knowledge was already in a tangible form. I had all the most interesting points from all the articles and books I’d read over years summarized succinctly on my computer. From there, it was a small step to making it into not only an online course, but the social media posts, blog posts, and videos required to promote that course. In other words, I didn’t start a business with some grand strategic plan. I didn’t even consider it a “business” until a couple years later. Instead, I built a portfolio of products one at a time, by converting my knowledge into formats that could be packaged up and sold online.

I don’t want to give the impression that starting a business was easy. I was often broke, barely able to pay the rent. I took many wrong turns, investing in projects that led nowhere. But my salvation was always my ability to create new content out of what I was learning. Some of my biggest failures became my best pieces of writing.

Starting a blog about a year later, I found that having a rich collection of notes at my disposal made writing much easier. All I had to do was gather a few related notes, string them together into an outline, add transitions and supporting points, and I could regularly publish long, detailed articles diving deep into topics that interested me. The blog soon became the key driver of my entire business. It functioned as an idea laboratory, allowing me to test out ideas before making them into products and services. It functioned as a marketing funnel, attracting readers with free content who later became paying customers. It brought me collaborations and partnerships, because people could see upfront what I stood for and what I had to offer. And eventually, I had enough posts to compile into ebooks, which I sold online to provide extra income.

At some point I realized that my digital notes were much more than a few interesting ideas jotted down somewhere. They constituted a “second brain” full of ideas, insights, theories, facts, research, and other valuable knowledge. I was able to accomplish difficult things – starting and growing a business, teaching thousands of people online, consulting with companies on their productivity, and coaching clients – while working no more than 30 hours per week, traveling extensively, and pursuing hobbies like sailing. I was able to produce a lot of content, writing hundreds of blog posts and 5 books, without being a full-time writer. My notes allowed me to live a life of creative and intellectual exploration without sacrificing security and quality of life.

Talking to my customers about the struggles they faced with their productivity, I realized that everyone could benefit enormously from such a tool, but that almost no one had one. Note-taking is a universal way to save and interact with knowledge that goes back hundreds of years. Yet no one teaches it, not in the workplace and especially not in digital form. We are expected to consume huge volumes of information in our work, and then we spend our free time reading books and listening to podcasts. Yet so little of this valuable knowledge gets saved and put to use. I knew that I had something that could change this situation, and that people would benefit so much from not trying to keep it all in their heads.

I set out to develop the world’s first course on what I began to call Personal Knowledge Management. I wrote blog posts describing my approach and got feedback as people tried what I recommended. I gave talks advocating for a new way of thinking about knowledge management. I started doing live trainings walking people step-by-step through setting up a note-taking system. And eventually, I put everything I had learned into an online course called Building a Second Brain. That course has now been taken by more than 3,000 people from all over the world, in a wide variety of industries and professions. Every day I receive testimonials on how it has given them freedom and clarity in their professional lives, as well as the confidence to take on new creative challenges.

I’ve had the privilege of serving tens of thousands of people with my online courses, and hundreds of thousands with my content. I’ve worked with many of the most prestigious and influential companies, governmental agencies, and non-profit organizations in the world – such as Toyota, Nestle, Genentech, Sunrun, and the Inter-American Development Bank – helping them maximize the potential of their institutional knowledge. Most gratifyingly, I’ve received many messages telling me stories of how building a second brain has made such a difference, from entrepreneurs in Argentina, to college students in North Carolina, to NASA scientists, to well-known writers and intellectuals.

At each stage of my journey, I’ve found that having my research, my knowledge, and my ideas in a tangible, external form allowed me to adapt more quickly, bounce back from disappointments and failures, and produce value no matter what situation I found myself in. Having a second brain has very much been like having a loyal collaborator and thought partner. When I am forgetful, it remembers. When I lose the plot, it reminds me where we’re going. When I’m stuck and at a loss for ideas, it seems to always point the way forward.

I’ve come to believe that knowledge management is one of the most fundamental challenges, as well as one of the most precious opportunities, for people today. How many books and articles do you read every year? How many podcasts and videos do you consume? How many courses or conferences do you attend? How many interesting and insightful conversations do you have? How much have you learned in your job and over the course of your career?

What have you done with all this knowledge you’ve gained? Where is it? What do you have to show for it? We feel this pressure to constantly be improving ourselves, to constantly be learning, but so much of what we consume just goes in one ear and out the other. We invest countless hours of our lives reading and consuming the knowledge of others, yet so few turning it into something of our own.

The course I created to teach everything I’ve learned is called Building a Second Brain. It is an online, cohort-based course on personal knowledge management. The course teaches participants how to capture, organize, and share their valuable knowledge using digital tools. Instead of allowing ideas and insights to slowly fade from memory, it provides a systematic approach to cultivating and resurfacing them over time.

Building a Second Brain draws on my work with Silicon Valley startups, multinational corporations, freelancers, entrepreneurs, and professionals that have to manage a large volume of information and deploy it effectively under high-stress conditions. All of us now have to manage large volumes of information to do our jobs and simply live our lives, while simultaneously doing our best and most creative work. It’s up to each of us to curate that information for lifelong learning. We can build a robust collection of personalized and useful knowledge to take from job to job. Such a collection can help us make unusual connections between ideas, incubate ideas over long periods of time, provide the raw material for new creative projects, and create opportunities for serendipity.

By offloading our thinking onto a “second brain” – a centralized, digital repository for the things we learn and work on – we free our mind to imagine, create, and simply be present. We can move through life confident that we will remember everything that matters, instead of floundering through our days struggling to keep track of every detail. This gives us the confidence to take on new creative challenges that have a greater impact on our organizations and customers and colleagues. The ability to capture things we learn, recycle and resurface our ideas, and retrieve them right when we need them becomes a cognitive superpower, amplifying our intellectual and creative abilities while preserving our time and peace of mind.

I’ve distilled everything I’ve learned about personal knowledge management into one unified curriculum, providing a blueprint for using technology to extend and expand the capabilities of the human mind. If you ever wished you could learn faster, work less, or more effectively manage all your ideas and projects, then you’ll definitely want to build a Second Brain.

Thank you to Zhan Li, Jaylene Wallick, Jordan Ayres, Thiago Ghisi, Cam Houser, Hibai Unzueta, Ben Mercer, Ablorde Ashigbi, Deepum Patel, Deepak Rao, Evan Driscoll, Alexander Hugh Sam, Juvoni Beckford, David Perell, and Alex Schleber for their feedback and suggestions on this piece.

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