Students estimated how long they'd need to finish their thesis: 34 days on average. It actually took them 55. More striking, their “if everything goes wrong” estimate was 49 days, still too short. Only 30% finished within their own prediction. The planning fallacy hits even people who know their past projects ran late.
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.