I genuinely don't understand why everyone isn't using this yet. Andrej Karpathy, OpenAI co-founder, posted a simple idea that went massively viral: Stop using AI to write code. Use it to build a second brain. You point Claude Code at a folder. Drop in any source: an article, a... transcript, a PDF. Claude reads it, links it, files it into a living wiki of everything you know. It compounds like interest. The more you feed it, the smarter it gets. Here's the whole thing: 1) Install Obsidian 2) Create a vault 3) Open it in Claude Code 4) Paste Karpathy's wiki idea and tell Claude to build it 5) Claude makes three folders: - raw (for sources) - wiki (for its pages) - CLAUDE. md (that runs it) 6) Drop any source into raw and say: "ingest this" 7) Ask questions across everything, forever Five minutes to set up and you never start from a blank chat again. Full step by step guide below.show more

The second brain only compounds if ingestion includes explicit summarization and link decay. Otherwise you end up with a bigger, slower version of the same unpruned history.

AI as a second brain is probably the most interesting use case right now

AI is evolving from simple chatbots to intelligent decision-making tools. That’s why Agentic Bro caught my attention $AGNTCBRO! Instead of just generating text, it analyzes X profiles, detects risks, and helps users spot suspicious activity in real time. Tested it myself the product is already live. Website: 𝕏 : @AgenticBro11 Tg: 
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52bJEa5NDpJyDbzKFaRDLgRCxALGb15W86x4Hbzopump Less hype. More utility.

They’ll start when it’s too late

"Compounds like interest" is the tell. It doesn't. Past a couple hundred notes the retrieval gets worse, not better, unless you bolt on actual RAG. And a second brain you didn't write yourself isn't a brain. It's a junk drawer with a search bar.

building a second brain because my first one failed

this is the way

Pruning is the missing step in most second brain posts

Most people are still asking Claude to summarize one doc instead of realizing it can be their actual knowledge base that remembers everything you've ever fed it. The problem is complexity or lack of wanting to learn. People love paying someone else to do it

Mentions Claude, uses Gemini with obsidian. Doesn’t explain what “the second brain” is for. These spam posts are too much

The folder as brain framing is underrated. When source material lives in the same place the agent works, it stops being a chatbot and starts being infrastructure

feels like note taking evolved into an organism suddenly

This sounds useful but I wonder how accurate it stays when you keep adding random sources

Honestly this sounds like a game changer, I might have to give it a go myself

The funny part: Karpathy's actual point was way more nuanced than the "second brain" repackaging. He warned about LLMs hallucinating connections across notes you'd never make yourself. Curation > ingestion.

This is why:

adding the second brain concept to my workflow made the whole thing way simpler

It looks cool, but only works if u have data genuinely personal, otherwise its just a cache

Perhaps because this is wishful thinking with a pretty Obsidian graph strapped on top?

is this comparable to replacing an enterprise rag?

Does he mean the video is the "full step by step guide below?"

Drift ftw!

That's such a powerful reframe! Using AI as a thinking partner rather than a code monkey changes everything. What kinds of sources have you been feeding into it? Curious what's clicking for you most.

I used it but it was to hard to maintain and brought me nothing

先把资料丢进去这步就劝退很多人了

this is the real ai use case

that's genius, clau codes like a human knowledge graph

We're moving from chatbots to personal knowledge systems.

そうだイーロンを真似しろ彼のTwitterは全てAI🦉

The compounding effect of organized knowledge is seriously underrated.

karpathy said one thing and the whole fintwit brain trust turned it into a 7 part guide lmao ur still not gonna use it bro be honest 💀

obsidian graveyard gonna have a new wing

I love this but it failed me. I built it with my vibe coding folder, several .mds, several skills, and Obsidian. I didn't know the wiki. Then I saw an app called @LittlebirdAI on Product Hunt. It handles the same kind of thing without needing to think about mds, wiki setup, etc. Does it with screenreading API. Syncs to phone. Obviously I had to join that company so pitched the founders, but I rec it to people who aren't going to maintain this stucture or need queries on mobile easily (I never got consistent results with Claude Dispatch but the wiki might help).