Arkes and Blumer posed a dilemma: you paid $100 for one ski trip and $50 for another you think you'd enjoy more, same weekend, no refunds. Which do you take? 54% chose the pricier one, the one they liked less. The money is gone either way, but the urge not to “waste” it wins: the sunk cost trap.
Remembering is not replaying a recording — it is rebuilding. Each time you recall a memory, it becomes temporarily malleable and can be altered before being stored again. That is why two people can sincerely remember the same event… differently.
In 2003, Johnson and Goldstein compared European countries. Where you must tick a box to become a donor, consent rates ranged from 4% to 28%. Where you're a donor by default unless you opt out, they topped 85%. People aren't more generous on one side; most simply stick with whatever option was chosen for them.