memory

You ignore how long an ordeal actually lasted.

When rating the discomfort of a medical procedure, patients disproportionately weigh the peak pain and the pain at the very end.

Global retrospective evaluations of pain are strongly predicted by the peak and end, but these are not the sole determinants of the memory.

Your memory is not a recording of time, but a snapshot of highlights.

Where this comes from

Study: Redelmeier and Kahneman, 1996, Pain
What the check found: While the 1996 Redelmeier and Kahneman study is real and established the Peak-End rule, the claim that patients rate pain 'solely' on these two points oversimplifies the study's findings regarding heuristic weight.
Confidence: Solid, with limits

One of these every day, and every one names the study it came from. When a finding is contested, it says so.