Why take pride in a cultural or ethnic heritage you know nothing about? I see this often. People identifying?

themselves as being ancestrally part of one group or another and even going so far as to identify with the often veritably caricaturized image of the culture as if it is part of their identity. Why have pride in being of say Irish ancestry if all you aware of is that the Republic of Ireland produces good stout lager or say German ancestry if you nothing except that they make efficient cars? Psychologically, it makes very little sense.