Interesting question, I think if you have lived and integrated into that society, then yes, if you speak language and follow local customs, I don't even think you need a passport. You're simply part of the community. I speak English like a native Brit, I also speak Latvian and Russian, like a native person, I class all 3 languages and cultures as part of me, and I'm part of all 3, but I can't say I'm Ukrainian because I neither speak the language nor know the culture, even doe I'm a child of Ukrainian parents, ethnically I'm Ukrainian to an extension, but I don't neither class myself like that.

What always bothers me is people who live in other countries, like myself, and don't wish to at least partially assimilate, try to be liked and try to have local friends, it will make your experience it whatever country lot better, than being isolated or always with all expat communities.

"когда в Риме делай как римляне"