Pie

As noted in this comment at unfogged, I once learned not to call myself Irish:

Not an analogy, of course, but I have a twenty-something Irish cousin who immigrated to the US in the last couple of years. We get on well, and one night after a couple of beers, I said something to the effect of "Yeah, I'm 70% Irish and 20% Polish..." Her face became immediately stern. "You are not Irish," she scolded.

She also thought it was weird that so many people here readily identify themselves via some pie-chart of background heritage percentages. "You're American*," she said.

I stammered about the diverse backgrounds of the people in this country, adding some bitterness about the term "American" for all its exclusions, and then I felt like an ass. It was a surprising and interesting conversation.

(Comity: we drank beer in my parents' garage, which was cross-culturally considered good**.)

*She meant USian, yes, I know. I currently prefer "Gringo" in describing my heritage.

**No, not because all Irish people are drunks, you prejudiced bastard.