Let’s start with the famous ones: the Navy SEALs. You’ve seen the movies, but the reality is even weirder. Fun fact: their Hell Week training involves running on wet sand while carrying a log that’s bigger than your couch—and they do it while singing motivational songs about their mothers.
One former SEAL told me they once had to swim in a bay so cold that hypothermia was a side dish to breakfast. If they quit, they just ring a little brass bell, which sounds polite, but it’s actually the sound of their dignity evaporating.