In 1969, Robert Zajonc had cockroaches run toward darkness, with or without cockroach “spectators” behind a clear screen. In a straight runway, they ran faster when watched; in a complex maze, they slowed down. It's social facilitation: an audience boosts what you've mastered but hampers what's hard. The same goes for humans.
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.