I'm a German-Mutt, My grandfather on my dad's side is half-german/british, my grandmother on my dad's side is 100% polish, then course on my mom's side there's british, cherokee, and a little bit of dutch in there somewhere. Yet my father insist we're from a german background when I'm probably more polish than German. And I did live in Germany for 3 years when my dad was stationed over there.
PS: Most Oktoberfest in the US is anything but authentic. Serving bratwurts on a regular hot dog bun... whats wrong with em, where's the f-in brochen?