[Huh. Judging by the lack of blank staring, he could read modern Japanese, too. Wonder of wonders.]

The answer, my dear Ellis, is plain old technological advancement.

Believe it or not, the buildings from your time and the others preceding it are the true marvels. There's a whole field of study dedicated to finding out just how those castles and pyramids were built, and a whole slew of conspiracy theories to entertain the ungrounded imagination.

Apart from that, what else do you know about this time? I'm sure zippers can't be that old, unless there's something they haven't dug up yet.