A rising full moon looks enormous. Yet photographed near the horizon and then high in the sky, it's the same size in the image, and it's actually slightly farther from you at the horizon. The effect happens entirely in your brain, and scientists have been debating its exact cause for over two thousand years.
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.