Kill your second brain

A vast echochamber advocates using notetaking software to create “a second brain.”

Joan Westenberg, who says she’s “built companies, advised startups, angel invested, and spent years studying how people think, build, and endure,” tried to create a second brain with Obsidian but ultimately deleted the 10,000 notes she had written:

The “second brain” metaphor is both ambitious and (to a degree) biologically absurd. Human memory is not an archive. It is associative, embodied, contextual, emotional. We do not think in folders. We do not retrieve meaning through backlinks. Our minds are improvisational. They forget on purpose.

Merlin Donald, in his theory of cognitive evolution, argues that human intelligence emerged not from static memory storage but from external symbolic representation: tools like language, gesture, and writing that allowed us to rehearse, share, and restructure thought. Culture became a collective memory system - not to archive knowledge, but to keep it alive, replayed, and reworked.

In trying to remember everything, I outsourced the act of reflection. I didn’t revisit ideas. I didn’t interrogate them. I filed them away and trusted the structure. But a structure is not thinking. A tag is not an insight. And an idea not re-encountered might as well have never been had.