What does it mean that tags are lightweight relationships?

A tag is the simplest way to declare that two atoms share something in common.

Example: You write a note about how your team's sprint retrospective keeps surfacing the same blockers. You tag it #decision-debt and #team-process. A week later, you write a separate note about how your personal habit of deferring hard conversations maps to the same pattern. You tag it #decision-debt and #avoidance. The tag #decision-debt now connects two atoms from completely different domains — team workflow and personal behavior — without you having to build a folder called 'Patterns of Avoidance Across Contexts.' The relationship declared itself through a shared label.

Try this: Open your note system and pick 10 recent atoms. For each one, add 1–3 tags that answer this question: 'If I had this same insight again in a different context, what word would I search for?' Do not overthink. Do not build a taxonomy first. Tag by instinct, then review your tags as a batch. Notice which tags recur. Notice which atoms are now connected that were not connected before.