Apparently I am someone else

or so it would seem.
As children we were "the teachers' kids" and, as my parents rose through the school system, "the heads' kids". My siblings, cousins and I were also "(my grandfather's) granddaughters and grandsons". I still get the latter once in a while. 
Now I sometimes get "the one who writes the letters to the paper" or "the one who rides the tricycle". A complete stranger came looking for me in the supermarket yesterday and said, "He told me to look for the person wearing the bicycle helmet."
I suppose there are, especially for me, worse ways to be described.
But it seems I am also someone else - or perhaps not someone. As a white, female of Celtic ancestry I really don't exist you know. I am not even "Greek" or "Italian" or "Maltese" or "Dutch" or a descendant of any of the other non-English speaking Europeans who make up part of the Downunder population. I am most definitely not Chinese, Vietnamese, Cambodian, Burmese, Thai, or Filipino. It doesn't count that my "Greek" nephew has the most wonderful Filipino-Japanese partner either.
For some reason none of those count. I am actually not allowed to say "I'm Scottish-Australian" but my brother-in-law is allowed and even expected to say "I'm Greek-Australian".
My paternal great-grandparents spoke both Gaelic and English. (My paternal great-grandfather began his working life as a sailor so English was essential. His wife was a very determined, self-educated woman who saw English as a stepping stone into the world of business.) Their children knew a few words and phrases. The Senior Cat's generation knew none at all. There should be none in my generation either but I do know a few words and so do several distant cousins.
You see, we wanted to know. Right around us there are people who claim another heritage, who are actually encouraged to claim that heritage. They are encouraged to learn the language of their ancestors - often with very little success but still done - and they are encouraged to "keep traditions". There are festivals and "cultural events". It is all supposed to be part of a "multi-cultural" country. So why are some of us being told we really aren't anyone. Why are we being told our ancestry doesn't matter? Is there something wrong with it? Should we be ashamed of it? The Scots have had a significant influence on science, technology, engineering, social systems, and more but apparently those things don't count. We apparently have no right to celebrate those things. 
I really don't understand this. If someone could explain I would be most grateful.  Tapadh leat.