He could’ve been switched at birth

If all my family was from Canada, we moved to the Ukraine, I'd be culturally Ukrainian but still ethnically not. If you grew up in the culture, it's silly to give that up if it doesn't match your ethnicity!

the obsession with what your blood says you are is mostly an American thing. It's a lot less common in parts of Europe. I've heard quite a few europeans express confusion at why americans feel the need to call themselves irish or german or whatever

Maybe they're so ashamed to be an american that they are trying to find an excuse to call themselves something else?

Also, in Italy there is no middle-ground. You cannot be ethnically Italian and not be culturally Italian too ;)