I bet you wouldn't think it would be difficult to answer the question "Where are you from?" but for me it is. During my travels I am frequently asked this question. If I answer America I get the surprised response that you travelled from America for only a couple of days, or that must have been a long flight. If I answer that I'm from London there is surprise that I'm not speaking with a British accent.
There is a definite difference between where are you from and where do you live. For many people the answers to these questions are the same, but to expats like myself the answers are very different. In speaking with other expats they have encountered similar dilemmas when posed with the question.
It has gotten to the point that my answer usually is something along the lines of "I'm from the US, but I live in London."