In 1999, two psychologists asked volunteers to count passes in a short basketball video. Midway through, someone in a gorilla suit strolls into the scene and thumps their chest. About half the viewers never noticed. Attention works like a spotlight: whatever falls outside the beam can vanish, even when it's right in front of you.
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.