Imagine you’re about to buy a used car. The seller names a price that feels far too high, yet somehow your counter-offer ends up much closer to that number than you planned. Later you wonder: why didn’t I stick to what I knew was fair? The culprit isn’t the seller’s charm — it’s a quirk in your own mind. In this chapter we’ll meet the mental shortcuts and hidden errors that routinely derail even the smartest negotiators, and we’ll learn practical ways to think more clearly when the stakes are real.