[blue11]

"Could have gone for citizenship, but didn't. I was never seen as an American."

Perhaps you were not seen as an American because you yourself didn't feel that way? I would think that someone who feels American would apply for citizenship given the opportunity. American citizenship does not bring many additional advantages compared to the green card, in fact, there are some downsides (jury duty, potentially having to pay US taxes even if you leave the country). So, most immigrants apply for US citizenship only if they feel that they belong.

I agree that people asking where your accent is from is really annoying, however, that question doesn't have the same implications as in, say, Germany.