Identities are funny things. It seems that the more secure we are in our identity, the less need we have to display it. Think about it, the quarterback for the Atlanta Falcons would not paste Falcons memorabilia over his car - but a fan would, trying to identify with the Falcons. The more secure we are in our identities, the less need we feel to advertise for them. The understanding is that those who are close to us already know our identity, and theirs are the opinions that are important. Our identity is central to how we see ourselves, but everyone places different importance on different aspects of their identity.
Nationalities are a funny thing too - they're part of our identity, but function differently to different people. My husband just became a US citizen. That means that he's now an American. At the same time, if I were to become a Moldovan citizen (his nationality), I would probably never be considered a "Moldovan" - just like if I were to become a Russian citizen or a French citizen I would never be considered Russian or French. And I think that's because I didn't take part in their shared history. It is the shared history that solidifies a culture, and most nationalities are protective of their shared history - they take pride in their national struggles and triumphs. America is different because the nation's cultural identity is that of a melting pot - all are welcome, all can call it home, and the countries' identity lies purely in its diversity. How I wish some days that I could be a Moldovan... (with, of course, all the privileges of an American...) They hold a type of pride in what they've survived, and what they've triumphed over, and I cannot share in that. I'll always be an outsider there, even if I were to live out the rest of my days there.