How my second brain works | Build Your Second Brain Series (1/10)

A “second brain” system is built to solve a common frustration: ideas don’t stay in memory, so information needs a place that captures it fast, organizes it cleanly, and makes it reusable later. The core workflow described here separates note-taking into four stages—capture, organize, distill, and express—so fleeting insights don’t vanish and useful knowledge can be retrieved on demand without relying on internet access.

The system starts with “fleeting notes” (quick, active captures) and “permanent notes” (distilled, reviewable knowledge). Fleeting notes are gathered the moment something is useful—annotating books and articles, saving a URL, or dropping a thought—then later turned into permanent notes through a structured distillation process. A key example is how a concept is traced back to its source: a note about “fleeting notes” is linked to a specific book (“How to Take Smart Notes”) and even points to a location number, so review can happen both from the note and from the original text.

For the capture layer, the setup relies on four free tools. Obsidian becomes the central workspace for notes. Zotero acts as the reference manager for papers and metadata, with a browser extension that automatically pulls in PDFs and bibliographic details. Google Keep is used for speed and flexibility—voice capture via “hey Google,” screenshot/image capture, and even searching text inside images—so ideas can be captured while walking or driving. Google Drive stores project files in a shared repository. The workflow emphasizes that capture must be quick enough to prevent ideas from evaporating.

Organization comes next, with a deliberate pause between capture and organizing to avoid dumping too much into the system. The organizer approach uses a PARA-like spirit but the creator prefers Johnny Decimal for flexibility. The practical method is consistent folder structure: when a new project begins, matching folders are created in Zotero and Google Drive. Documents go into Zotero, while source code stays in Google Drive; Google Keep is treated as the messy inbox for rapid intake.

Distillation turns raw material into layered, future-proof notes. The method highlights main points, then highlights the main points of those highlights, building essence through multiple layers. Notes are written in bullet form for readability, and the process includes “empathy for future self”—structuring notes so the meaning can be reconstructed years later.

Zotero’s PDF reader and annotation tools play a central role in distillation: annotations made while reading are extracted and converted into a clean note with images, which then gets transferred into Obsidian. The same pipeline applies to Kindle, where book highlights and annotations are extracted into Obsidian.

Finally, “express” is treated as the reason the system exists: publish papers, write blog posts, and produce videos. Two standout capabilities reinforce reuse and retrieval—bi-directional syncing between Obsidian and Zotero (including jumping back to the exact source location) and Obsidian’s graph view, which connects notes and references like a network of neurons, making relationships easier to spot and knowledge easier to apply later.