If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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I don't know about that -- the Odyssey, for example, doesn't have any trouble with the idea of a false identity...
Technically you are correct, of course, I don't know if the concept of false identity would have made sense to a paleolithic tribe, and if it did we can always go earlier until it wouldn't. But at this stage, a LOT of contemporary concepts would disappear.
As to your game, I think you need to limit it in some way, otherwise too much stuff (from women's rights to telecommunications) qualifies.