A useful way to think about this: convexity is what reminds you that bond price sensitivity is not perfectly linear. Desk note: Duration gives the first approximation. Convexity tells you how that approximation changes when the move is large. Why investors care: That matters most when portfolios are built assuming small yield changes and reality refuses to stay small. Translate it into behavior: On bigger rate moves, the second-order effect can materially change how a supposedly simple duration bet behaves. Where people usually get tripped up: The mistake is relying on first-order intuition when the regime is delivering second-order moves. Keep this nearby on the next review: A useful review question is which funding, incentive or cash-flow channel is actually doing the work. A lot of confusion disappears once you separate the headline from the mechanism.