Anyone else's family have this? When someone says, "It's a challenge." You immediately have to do the thing, regardless of how stupid?
Like a sibling says "wouldn't it be funny if you chugged that can of olives?" And I go, that's a challenge. He just immediately tries his best.
(Never actually had someone do that I just can't seem to think of a good example at the moment.)
Tossing people into the pool is a good one.
Or chugging drinks.
(Bet you can't finish off the milk, pause, laugh, then completely dead serious. "that's a challenge btw" and bro proceeds to chug the rest of it from the container.)