What is Second Brain?
A personal system for capturing, organising, and connecting knowledge outside your biological brain. The term, popularised by productivity author Tiago Forte, describes an external repository where insights, notes, and ideas remain searchable and useful over time rather than being forgotten.
My perspective
In practice
A second brain ranges from a simple note-taking app to a Git repository connected to AI agents. What matters is systematic capture (save what resonates), reliable retrieval (find it when needed), and regular review (connect old ideas to new ones so they compound).