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.