In 1956, George Miller made the “magical number seven, plus or minus two” famous. But when people are prevented from rehearsing or grouping items, working memory's real capacity drops to about four chunks, as Nelson Cowan's review showed. If you can hold a phone number, it's because you split it into chunks.
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.