A worked example of [[Build a Second Brain|building a second brain]] at personal scale, traced through [[Knowledge mapping|the three acts]]: decompose what a question depends on, place each piece in its container and judge its state, then match a method. Single-person scope, so holder and owner are both just "self"; the walkthrough is the climb from scattered apps to one durable source. ![[Second brain example - personal notes.canvas]] ## Summary 1. Prompt *"what's my current take on X, after all I've read?"* - its cone scattered across years of apps 2. Notes split across two abandoned apps (🟠 stale), the connections never written (🔴 absent), the synthesis 🟣 tacit, no single place holding the latest (🟡) 3. Consolidate into one portable linked graph ([[Zettelkästen]] + [[Build a Second Brain|BASB]]) 4. [implementation] [[Obsidian]] ^summary ## The acts in one line each Prompt *"what's my current take on X?"* decomposes into the source notes, the links between them, and my synthesis - a cone that fans out across five years of apps; most links were never made and the synthesis never left my head. ^trail-line Where each piece lives: the source notes sit in two abandoned apps (🟠 stale, hard to export) and one current one (🟢); the connections were never written (🔴); the synthesis is 🟣 tacit; and "which note holds my latest view?" has no single answer (🟡). Container for the tacit half: my own head - bus factor of one. ^profile-line Consolidate every scattered note into one portable graph (single source), link what was loose, capture what was only in my head - a [[Zettelkästen]] + [[Build a Second Brain|BASB]] approach, landing on [[Obsidian]]. ^method-line ## Full walkthrough ### Act 1 — dependencies Start from a real question: *"What's my current take on X, given everything I've read about it?"* Decompose what answering it depends on: - my **synthesis** of X - the conclusion itself; - which depends on **how the sources connect** - the relationships between what I read; - which depends on the **source notes** themselves - one per book, article, or talk; - which depend on those notes having been **captured and kept findable** in the first place. Traced down, the cone fans out across years of note-taking. The leaves are concrete: a 2018 set of notes, a 2021 set, the connections that should tie them together, and the synthesis on top. Structure only - where each leaf lives, and what state it is in, is the next act. ### Act 2 — containers Place each leaf in the container that actually holds it, and colour it: - **Notes from 2018 reading** - in Evernote, an app I no longer open and whose export is awkward: 🟠 stale, in a locked format. - **Notes from 2021 reading** - in Notion, written and still findable: 🟢 defined. - **How the sources connect** - never written anywhere: 🔴 absent. - **My synthesis of X** - only ever in my head: 🟣 tacit. Its container is *me*, and the bus factor is one. - **My latest view on X** - scattered across Evernote, Notion, and Apple Notes with no way to tell which is current: 🟡 no single source. The board makes the diagnosis visible: a single prompt whose cone is half-stranded in dead apps, half in my head, the connective tissue missing and no single place to look. An agent - or future me, after another app switch - could not answer it. A board for this example: [[Second brain example - personal notes.canvas|the cone, coloured]]. ### Act 3 — method Read the move off each colour, and the method falls out: - 🟣 tacit synthesis → **capture** it into a tool; - 🟡 scattered latest-view → **single-source** it: one note, one place; - 🟠 stale 2018 notes → **migrate** them into the durable tool and drop the dead app; - 🔴 absent connections → **link** the notes into a graph. Every move points the same way: one portable, linkable store. The method is a linked graph built on plain text - - [[Zettelkästen]] - atomic notes, structure emerges from links rather than folders - [[Build a Second Brain|BASB]] - the capture → organise → distill → express workflow that keeps the graph alive - with two non-negotiables: *one source*, and *the data survives the tool* ([[File over app]]). The accountable owner, at personal scale, is simply me. ### Tool (illustrative, after the workshop) Obsidian - plain-text markdown, local-first, graph view, plugin ecosystem. The tool followed from the method; the method followed from the board. Had the non-negotiables been different (e.g. real-time collaboration above all), the same walkthrough would have landed on a different method and tool.