Nationalities - What are we?

I have been doing some reading about how in the Byzantine empire every walk of life existed in peace until one day a man stood up and realized his family several hundred years came from Greece and started loose pride for Byzantine and gainned pride for greece though his family had been out of Greece for several hundred years(I know Greece was part of the Byzantine Empire). Others started doing the same and of course one nationality thought they were better then others and problems between people started to emerge later on contributing to the collapse. After the collapse greece and other nations were restored. The United States has people from all over just like the Byzantine Empire did with more pride for their ancestors former country then their own. Currently it seems there is a sterotype for each Nationality.

Just thinking! Me, both my parents and all my grandparents were born in the United States and have american citizenships. All of my great grandparents on my fathers side came from Greece and my great grandparents on my mother side came from Germany, Ireland and Scotland(came meaning they got on that boat, traveled across the atlantic checked in at ellis island and started a new life in new york). Regarless of my nationality I am 100% human like you and that should be all that matters.

I have a sister who brags about being greek to family and friends though we have never been to Greece and we are the fourth genetation americans. First question. When do we stop bragging about being greek. Maybe tenth generation? or by the time you become less then 15% greek (thinking about future generations). The factor of the matter is all these meaningless braggings just makes her look like an arrogant fool.

Now in order to be greek by great grandparents would have once had to live in Greece. Odds are that if we went back a couple of generations my greek ancestors would have most likely came from another country whether it was in their lifttime, 4 generation before them, or 4 centuries before them. Lets get say my great grandparents, great grandparents came to greece from Italy does this mean my great grandparents use to brag about being italian? If this ends up being true does this mean I should start telling people im italian? If i decide to move to Canada and have children, will my Children brag about being American, Canadien, Greek, or all three? What do you think?

The point im trying to make is why do people who are several generations in brag so much about their "ancestors" nationality when 90% of them will never go to their "ancestors"home country or bother to learn the language? Alot of them don't even know the history of the nation or current affiars of the nation they are bragging about. What if the history was all about tyranny is that something to be bragging about? Being human is all that should really matter.