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 | 92 | Founded | a year ago | Last Issue | 8 days ago |
| Active | |||||
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secondbrainnotes.substack.comLatest Issues
The Delusion Tax
Picture two people starting the same business on the same day, with the same savings, the same skills, and the same market.
Eighteen months later, one of them has a real company.
How To Measure What Actually Matters
You're tracking a dozen numbers and none of them are the one that matters. The Scoreboard Audit finds it in under ten minutes.
You have eleven tabs open right now that are tracking something.
Your Brain Isn’t Building For 2026
Building better brain with different habits, thinking how to sharp mind in 2026.
You blame willpower.
You blame discipline.
You blame yourself.
None of that is the real problem.
The real problem is that you are running stone-age soft...
Your Attention Span Is A Longevity Metric
Here’s what nobody’s telling you: a fragmented attention span isn’t just a productivity problem.
It’s a biomarker.
The same stress response that makes you check your phone every four minutes is the one flooding your body with cortisol e...
Key Facts
Audience Metrics
Subscribers, engagement, traffic and sponsorship for The Second Brain.
| Subscribers | Engagement | 80 | Monthly Web Visits | ||
|---|---|---|---|---|---|
| Accepts Sponsors | Estimated Cost per Ad | ||||
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Authors
The writers behind this newsletter.
I write about ambition, mental resilience, and the modern mind. Author, The Second Brain. Building Sona.
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