Something that occurred to me the other day regarding my own "memories" of times before I was born:
From 1965–Present, the world is in color. The tone shifts a bit, but it's all in color.
1900–1964: Black and white. The world was actually black and white. Sometimes people moved around at a weird frame-rate :)
1800–1899: Color, but very much sepia toned. The whole world was slightly dirty and brownish, but the sky was still blue.
Big Bang–1799: Color, no sepia or nothing.
Of course this is all due to photography and movies. The general lack of both of those before the 20th Century (yeah, I know photography goes back further, but just barely. It wasn't widespread) means whatever images I get from that time period come from paintings and illustrations and written accounts. The sepia I perceive from the 1800s is basically thinking of them in terms of the railroads, westward expansion, etc.
So the result is that when I think about the Roman Empire—when was the last time you thought of that?—I see a richly-colored world like the one we have today. But when I think about WWII, it's all black and white. And the Civil War occurred in a vast, dusty, brownish field.