3-Year Update: A Financial Analysis of My Book’s Unit Economics

Building a Second Brain book under a microscope

It has now been 3 years and 3 months since my book Building a Second Brain came out in the U.S., and I’ve just received word that it has now earned out its advance! That probably doesn’t mean anything to readers, but to me as an author, it means a ton. It means that the…

A Guide to the Claude 4 and ChatGPT 5 System Prompts

One of the most influential yet under-appreciated parts of how large language models work is something most people never see: the system prompt. This is the block of hidden instructions given to the model before it ever receives your input. It establishes the model’s tone, boundaries, and behaviors. You can’t change the system prompt, but…

Mushroom Trip: My First Experience with Psilocybin-Assisted Therapy

I’ve noticed that psychedelic medicine has been on the rise in California and other parts of the U.S. over the last few years, and have heard reports from a handful of friends and acquaintances about the incredible results they’ve had from ketamine, MDMA, and psilocybin. In our new home of Valle de Bravo, Mexico, I’ve…

Life and Death on a Scorched Planet: What I Learned From “The Heat Will Kill You First”

I remember the exact moment I was radicalized about climate change. Standing on the front porch of our new home in Southern California in the summer of 2020, I watched the sky turn a burnt orange as wildfires blazed in the inland summer heat. The particles of smoke didn’t just fill the air—they filled our…

My 4-Stage System for Learning Anything New

You discover something fascinating—maybe it’s vibe coding, sustainable investing, or sourdough baking. Your excitement builds as you imagine mastering this new skill. But then reality hits: Where do you even start? The internet offers endless tutorials, courses, and “ultimate guides.” Your bookmarks folder grows heavy with resources you’ll “definitely check out later.” Weeks pass, and…

What J Dilla and Early Hip-Hop Teach Us About AI and the Future of Creativity

What J Dilla and Early Hip-Hop Teach Us About AI and the Future of Creativity

In 1997, a young hip-hop producer from Detroit named J Dilla did something that violated every rule in music: he programmed his drum machine to play “off beat.” Not just slightly off, but deliberately off—breaking up the rigid timing that had governed musical performance in every genre. What happened next confounded the music industry. Instead…

Introducing Death Clock (And My First Experience with Vibecoding)

Death Clock

I’m proud to introduce Death Clock, a life expectancy calculator that predicts the day of your death based on 17 personalized variables. Give it a try for free! This is not only the first “app” I’ve ever created myself, but also my first experience with AI-assisted coding, which has become known as “vibecoding.” I can…

Productive Disorder: The Hidden Power of Chaos, Noise, and Randomness

Productive Disorder

In the early 1700s, Central Europe faced a crisis: the forests were running out. An explosion in mining, shipbuilding, and early industry had devastated old-growth forests that had stood for many centuries. Meanwhile, the population was exploding as well, creating demands on forests that clearly couldn’t be sustained for long. The kingdoms of Prussia and…