Yes, no one can ever no anything about a counterfactual. So does nothing matter beyond whatever each individual chooses to matter? (Nihilism / Hedonism.)
I meant more in the sense that we are primed to take one side of the issue by the default, the one we know. In the counter-factual Socrates-less world I'm describing, we are the unprovable counter-factual and people there are posting about how grateful they are that Eulogothenes' words were put to papyrus.
Perhaps a better way to illustrate this is to point out that the Mona Lisa's cultural prominence essentially ballooned once it was stolen.
