I'm from a town where, growing up, I always thought/"knew" it was "normal" that every other kids' parents (just like my own parents) were from somewhere else. So, my own parents were immigrants to England; many of my friends at school had Kenyan, Portuguese, Polish, Italian, Spanish, Nigerian, Goan, Jamaican and Irish parents; one of my closest friends had a Welsh father and a Seychellian mother; many kids in town had Sikh parents and Hindu parents and Muslim parents and Jewish parents and Christian parents and honest-to-god atheist parents, and those parents of those English kids were from various countries around the world.
When I was 14, I remember chatting with a schoolpal, Paul O'Hara. I'd always assumed (with a name like "O'Hara") that Paul's parents (just like absolutely eeeeeverybody else's parents) were from "The Old Country", from Ireland. And so Paul and I were talking. And he mentioned something about one of our teachers, Mr Andrews, who "was teaching here when my Dad was at this school" - which caused me to do a double-take: "Woh, homie! Back up a bit there: what did you just say? Your Dad used to attend the same school that WE attend?! Your Dad is from this town?!" And Paul said "Yeah. So's my Mum." And then it hit me, all of a sudden: NOT EVERYONE has family roots in other places! Some kids actually have family roots in this town, going back several generations!
And, once that shocking reality had struck me, I started to notice that there are some towns in England (and in the UK generally, and in the world more widely), where it's actually "normal" NOT to have any ethnic diversity at all; there are towns around the world where it's actually "normal" that the majority of kids have parents and grandparents who are also from the same town. That was quite an eye-opener for me!
What about the place you're from? Is "everybody" from there, or are a lot of people's parents relatively "new" arrivals?