So much of cultural and technological development is bound up in stuff that seems perfectly obvious in retrospect, but depends on such a vast array of idiosyncratic assumptions and random factors lining up just right that if we ever meet aliens, I’m betting the thing we’ll end up being known for in the galactic community will be something simple and goofy that we came up with not because it required any special insight on our part, but because, through sheer, dumb luck, we just happened to be the first to think of it.
sandwiches.
food wrapped in flatbread (shawarma, burrito, gyro, etc.) appeared independently everywhere so I’d assume it’s really easy to invent
but sandwiches look like they’ve been invented by Europeans very recently and then spread