What is knowledge hubs?

Knowledge hubs is a concept in personal epistemology: Nodes with many connections are core concepts that deserve extra attention.

Example: Open your note graph and sort by link count. The top 5% of your notes — the ones connected to dozens of others — are your hub nodes. In a Zettelkasten of 500 notes, roughly 25 will have ten or more links. These aren't your longest notes or your most polished ones. They're your most connected ones: 'feedback loops,' 'mental models,' 'cognitive load,' 'second-order effects.' They are the concepts you keep returning to because everything else touches them. Lose one of these nodes and dozens of connections go dark.

This concept is part of Phase 18 (Knowledge Graphs) in the How to Think curriculum, which builds the epistemic infrastructure for knowledge graphs.