[Mal cocks his head in mild confusion when Eric mentions Vikings as explorers and conquerers.]
But... That ain't how the history teaches it. Those that lived on Earth-that-was was all settled. That's why y'all had to leave. You used up the Earth. S'why we're out among the stars now.
[The simple confusion of Mal coming from 2517 while Eric is talking about a time he's never even thought of. And his education wasn't always perfect...]