I think the point that the parent post is making is that while one can learn to be proficient in a certain topic, he/she can't call it "native" unless it is in

I think the point that the parent post is making is that while one can learn to be proficient in a certain topic, he/she can't call it "native" unless it is in fact, "native" in definition. It's as much as you can't claim native to a specific country if you are not born/raised in that country.