Backlinks are essential for zettelkasten systems because they create bidirectional connections between notes, enabling discovery of unexpected relationships over time.
Unlike hierarchical filing systems, backlinks mirror how knowledge actually connects in your mind - laterally and in multiple directions. When you reference an older note in a new one, the backlink lets you later discover that connection from either direction.
The key benefits:
- Serendipitous discovery: Patterns emerge you didn’t consciously plan
- Compound knowledge: Old insights resurface and combine with new ones
- Natural associations: Ideas connect across different domains
- Active memory: Prevents notes from becoming isolated and forgotten
Without backlinks, you lose the core advantage of zettelkasten - the ability to have an ongoing conversation with your accumulated knowledge where ideas can cross-pollinate and evolve.
The system only works if you actually follow the links during regular review sessions.