The Second Brain
David TostYour gut controls your mood. AI is reshaping therapy. Longevity science is going mainstream. This is where mental health, technology and performance collide.
| Platform |  | Pricing | Freemium | Publishes | Daily |
|---|---|---|---|---|---|
| Issues | 56 | Founded | 7 months ago | Last Issue | 8 days ago |
| Active | |||||
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secondbrainnotes.substack.comLatest Issues
Build A Mind You Actually Want To Live Inside
You spend roughly 16 waking hours a day inside your own head.
If that head were a house, would you actually want to live there? Most people, if they sat down and were honest about it, would say no.
The lights flicker, the walls are plast...
How To Use AI Without Getting Dumber
Here's the uncomfortable truth nobody wants to put in a LinkedIn post:
Most people are going to get dumber because of AI.
Not in some sci-fi, brain-rotting, Black Mirror way.
It’ll be quieter than that.
They’ll just stop thinking.
T...
You Won't Recognize Yourself In 12 Months. If You Do This.
I’m going to make you a promise.
If you do what I’m about to lay out for the next 6 to 12 months, the person reading this article will not be the person who finishes it.
Different body. Different brain. Different bank account. Different f...
How To Add 10 Years To Your Life (Without The Biohacker Nonsense)
Walk into any gym in 2026 and you’ll see them.
The guy with the continuous glucose monitor checking his phone between sets.
The girl drinking a $14 mushroom-collagen-creatine-electrolyte concoction that tastes like dirt and hope.
Someb...
Stop Journaling. Start Living: Why Over-Journaling Is Secretly Sabotaging Your Growth
For years I was that guy. Morning pages.
Capture-everything protocols.
Future-self notes.
End-of-day reviews that turned into full essays in my second brain.
I genuinely thought I was doing the inner work.
But one day I looked around...
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Authors
The writers behind this newsletter.
Creative Director & Founder. I write about ambition, mental resilience, and the modern mind. Founder of The Second Brain
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