In 2005, Swedish researchers showed volunteers pairs of faces and asked which was more attractive. Then, with a sleight of hand, they sometimes passed over the rejected photo and asked why it had been chosen. In more than seven cases out of ten, nobody noticed the swap, and some justified their “choice” with features absent from the face they'd actually picked, such as earrings. It's called choice blindness.
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.