Yesterday's XKCD cartoon made me laugh. Click the image to be taken to a larger version at its Web page (and don't forget to move your cursor over the image there to see the mouseover text).
I suspect a lot of contact between civilizations has been along those lines, on Earth as much as in interstellar or intergalactic terms. Just think of the number of countries and cultures that considered themselves superior, or advanced, only to be discovered by others who found them the exact opposite - perhaps because the new arrivals were so conditioned to think themselves superior that they couldn't see the achievements of those they'd "discovered". How often do we do likewise, in terms of assuming that our outlook on anything - political, social, economic, cultural, whatever - is necessarily superior to others' perspectives? (The cultural and economic clashes in China between East and West during the 19th century, epitomized by the "Opium Wars" and the "Unequal Treaties", come to mind, as does the colonization of just about any country you care to name.)
An amusing cartoon, but also a sobering thought.