We are exposed to more information in a single day than a 15th-century scholar encountered in a lifetime. The problem isn't access to knowledge — it's building a system that lets you actually use what you've learned.
The Three Schools of PKM
- Folder-based. Familiar, but inflexible.
- Tag-based. Flexible, but requires consistent discipline.
- Link-based. Mirrors how ideas actually relate — steeper curve, deeper reward.
Obsidian: The Best Tool for Networked Thinking
Obsidian stores everything as plain markdown files on your local machine — no proprietary format, no cloud dependency, no subscription for the core product. The graph view becomes genuinely useful once your system exceeds a few hundred notes.
"The goal of a second brain isn't to remember everything — it's to think better." — Alex Kim
Notion: The All-in-One Option
Notion remains the most versatile tool: part note-taker, part database, part project manager, part wiki. Its AI features can summarise, extract, and query your notes automatically. The trade-off is complexity and performance at scale.
What Actually Matters
The best second brain is the simplest one that you actually use. Build the habit first; optimise the system later. The friction of switching tools is always greater than the benefit of a theoretically better one.