The day after the Challenger shuttle exploded in 1986, Ulric Neisser had students write down how they'd heard the news. Two and a half years later, many told a completely different story with full confidence, and some stuck with the new version even when shown their original account. After 9/11, a Duke University team found these vivid “flashbulb memories” faded just as fast as ordinary ones. Only the certainty stayed intact.
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.