Some people are born unable to recognize faces, even those of loved ones, despite perfect eyesight. It's called congenital prosopagnosia, and studies put it at around 2% of the population, many of whom never realize it. They identify others by voice, walk or hairstyle. The neurologist Oliver Sacks had it himself.
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.