Peak-End Rule
The Peak-End Rule is a cognitive bias that shapes how we remember past events, prioritizing the most intense moment (the "peak") and the final moment (the "end") over the total duration or average experience. Discovered by Daniel Kahneman in 1993, this mental model explains why we value an painful medical procedure with a gentle ending over a shorter, more intense one, and why IKEA sells cheap ice cream at the exit. Understanding the Peak-End Rule allows experience designers and leaders to create lasting positive memories by optimizing the "snapshots" that survive in long-term memory.