On jumping off of cliffs into water willingly, for fun! You see, that's very much not a normal behavior to any species but humans will see a cliff and a body of water that's deep enough at the bottom of it and be like "Is anybody gonna jump that" and not wait for an answer, to the chargrin of many alien companions. Imagine you're an alien and you're sent with a crew to explore a planet and there's a few humana in it and they just. Jump off of a cliff the moment you're on break. Imagine the terror one would feel, like, sure, it's known that humans are fond of water, they can swim kinda okay-ish, but- to toss yourself from a high altitude into a deep pool of water?! And then laugh once you come back up from the surface?? And then do it again and again???????? Like sure whatever, why the fuck not I guess
