What is a second brain? A guide for the AI age
A second brain is a place outside your head where you store everything worth keeping. Here's what it is, why it matters, and why AI changes what it needs to do.
Posts tagged Essays
LLM wiki vs. plain Markdown: when Karpathy's gist stops working
A plain Markdown file works for the LLM wiki pattern. Until it doesn't. Here are the five points where it stops working, and what to use instead.
What is a Second Brain? The AI-Native Take (2026)
A second brain is an external system for what you read, think, and decide. The traditional version is a graveyard. Here's what replaces it in 2026.
My Marketing Team Is Two AIs and a Knowledge Base
I run Hjarni's entire growth program from inside Hjarni itself. Two AIs, three folders, and a built-in MCP server. Here's the real loop, step by step.
Your Tools Do Too Much
Notion has 47 features you'll never touch. Obsidian needs plugins for everything. Both assume you want a system. You don't. You want to write something down, find it later, and let your AI read it too.
Karpathy's LLM Wiki is right. I just didn't want to run it locally.
Andrej Karpathy's LLM wiki gist nails it. Stop dumping documents at LLMs. Build a brain. Hjarni hosts the pattern over MCP, on every device and LLM.
Stop Explaining Your Codebase to Your AI Every Time
Your AI is smart but has no memory. Here are five notes that fix that — so every conversation starts with context instead of from zero.
Never Lose Your Startup's Knowledge
Learn how startups avoid information loss by using Hjarni's shared knowledge base.
Your AI Hit Its Limit. Your Knowledge Shouldn't.
Every AI conversation eventually resets. The real cost isn't the limit — it's re-explaining yourself every time. Your knowledge deserves a home you own.
I gave Claude access to my notes through MCP
I connected Claude to my notes via MCP. Setup took 2 minutes. Now every conversation starts with my project context already loaded — no pasting, no re-explaining. Here is what changed about how I work.
Write once. You both remember.
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Give your AI a memoryWorks with Claude and ChatGPT today. Gemini coming soon.