In 2013, a Harvard team asked 24 radiologists to look for lung nodules on CT scans. In the final case, they had inserted a gorilla 48 times larger than an average nodule. Twenty of the 24 radiologists didn't see it. Eye tracking showed most of them had looked right at it. Even for experts, what you're not looking for can stay invisible.
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.