What is two-way links?

Example: You write a note about 'sunk cost fallacy' and link it to your note on 'decision-making under uncertainty.' In a one-way system, you'd have to remember that connection existed when you later open the decision-making note. In a bidirectional system, opening 'decision-making under uncertainty' automatically shows you that 'sunk cost fallacy' references it — along with every other note that does. You didn't plan these connections. The system surfaced them because every link knows about both ends.

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