No real reference

Wandering the halls of an audio show it's always stunning to me how different the same music sounds. How can we say there exists a reference? If we're so bold as to suggest there is a reference, like that of the sound of live unamplified music in acoustic space, how do we justify the major differences in audio system reproduction? Could it be that as a group we're so far away from the true reference that our meager attempts are laughable at best? Or is it that we all hear differently? That what sounds right to me doesn't sound right to you? If this were true then a hundred people enjoying a concert would all hear something different. We'd have trouble agreeing that it sounded real, yet that doesn't happen. Or does it? Could it be that because we're actually at the concert no one would be silly enough to openly question whether it was actually live or not—yet none hear the same thing? I don't suppose there's a way to easily answer this question but I suspect if we compared listening notes there would be as much divergence of sound quality per listener at a live concert as we do in a reproduction setting. I would wager that the only real reference is what's inside your head.