Since I got to New Zealand, I have been asked that question more times than I can count--'Are you Canadian?'
It's quite obvious by my accent that I am not originally from here but people don't ask where I'm from unless we have more than a 2 minute conversation. When they deduce that I am either American or Canadian, 4 out of 5 folks will opt for the Canadian question as opposed to asking if I am from the US.
Interestingly enough, my answer is usually followed by the other person leaning forward a bit and saying, quite apologetically, that Canadians are insulted if you call them Americans!
Personally, I don't have a problem with being confused with being Canadian since it's a pretty close call. But I can't, for the life of me, understand why there is a problem from the other side.
I googled 'Why do Canadians hate being called Americans?' but was quite overwhelmed with the over-a-MILLION results. Obviously, I'm not the first one to ask that question on the internet and there wasn't a definitive answer in the few articles I read.
I don't get it. If you are Canadian, can you please enlighten me, eh?