Some random thoughts (serious this time)
One wonders if there could have been at some time a civilization that was advanced and then destructed (I'm not talking Atlantis here). Who's to say that we are the first? Could it not have happened and then disintegrated, perhaps due to the great flood? Just as we are here now but a hundred years from now, perhaps we won't be due to a meteor strike, volcanic eruptions blanketing the earth with ash or other disasters not excluding nuclear devastation. Then, 100,000 years from now, someone will find remnants of our civilization and wonder what it was, how it ended, if it was real, etc., etc., etc.