There's more to it than that though. Aside from global insularity, Americans have an extremely short psychological conception of history.

One of the reasons Russians remember history is they have a lot more of it. When your civilization is 1100 years old and a cultural descendant of the Byzantine Empire, your ideas around what to remember are significantly different than an American. People who care about The Current Thing™ or what one of the Kardashian sisters is doing at a given moment aren't going to even have the proper resolution or framing to think that way.