Convexity is what reminds you that bond price sensitivity is not perfectly linear. Three quick checks before you act: 1. Name the mechanism in plain English: Duration gives the first approximation. Convexity tells you how that approximation changes when the move is large. 2. Say why it matters for behavior or portfolio decisions: That matters most when portfolios are built assuming small yield changes and reality refuses to stay small. 3. Set the review question: A useful review question is which funding, incentive or cash-flow channel is actually doing the work. In practice: On bigger rate moves, the second-order effect can materially change how a supposedly simple duration bet behaves. Watch for: The mistake is relying on first-order intuition when the regime is delivering second-order moves. That is the kind of small conceptual habit that compounds into better decisions over time.