It is fine when we find an identity that diverges from the dominant culture. Our species remains the same, of course, regardless of the diversity of cultures.
I think this is a touchy topic even for people who are 100% of some ethnic group, but who live in a totally different ethnic group. For example "hyphenated Americans" like Filipino-Americans, Chinese-Americans, Cuban-Americans, etc.
Some get touchy when asked "where are you from?". For some people, this implies a kind of alienation and/or an attempt at marginalization, especially if the questioner says something like "no, I mean where are you
originally from?". I for one do not think this way, because of what you said there about "
diverges from the dominant culture". I think it's natural and I give people the benefit of the doubt that they are being curious, and not being either xenophobic or purposefully highlighting our differences.
Background is a culture. A culture can be large like an empire, or small like how a wizard university operates. A background can represent any of these.
I've always had difficulty saying I am half Filipino. It's the easiest thing to say, but it's not really representative of my mother's culture. About 5% of the Philippines (by population) are Moros; the mostly Islamic Filipinos. In culture, they are much much closer to Malays than their own kababayan (countryman). Even most Filipinos don't know their own history and I recall many conversations with Filipinos, who assuming my Filipino half is the Hispanicized/Christianized culture, bad mouth the "Moro terrorists" in what is today the BARMM (Bangsamoro Autonomous Region of Muslim Mindanao).
When my maternal grand parents were born, where they lived was not yet a part of the Philippines. Technically, the island they are from belonged to the Sultanate of Sulu, and they are close cousins to what is today Brunei and the Sabah region of Malaysia. That region of the Philippines was never fully conquered by Spain. The Moro languages, like Sama, Yakan, Tausug and Badjao are quite a bit different from the two other ethno-linguistic groups of the Tagalogs and Visayas. They have kulingtangan (gamelan) music just like the Malays and Indonesians, and more of their words are the same as Bahasa. For example, while Tagalogs say
tito and
tita for uncle and aunt, I call my elders
bapa and
babu which are the same words in Bahasa. And of course, their dominant religion is Islam rather than Catholicism. They wear malongs (a kind of tubelike skirt) and sarongs like Malays, and though somewhat antiquated now, my mother and grandmother wore kebayah dress like the Malays (and parts of South East Asia like Thailand).
It wasn't until the last Datu surrendered in 1913 that the Sultanate of Sulu finally capitulated to the Americans. So for only a little more than 100 years, where my mom came from has been a part of the Philippines. As I said, my grandparents weren't even born as citizens of the Philippines.
I've always felt a kind of spiritual kinship to American Indians, because I can empathize with your homeland being "assimilated" into a larger culture that really isn't like yours at all.