That is how I have had to reply to people all of my life. My light skin and hazel eyes drawing nothing but skepticism when most people ask, "What are you?"
My Uncle Ardy, who is no longer with us, use to laugh and call me "the Jerk" relating my dilemma to Steve Martin's character in the 80's film which had a white guy consider himself a part of black culture. When I worked in Head Start classrooms, Mexican parents would ask how I spoke Spanish so well and I would tell them that I am Mexican. In shock they would ask where I was from. I replied, "Mesa, Arizona". I went on to explain that my Nana Grandma came from Mexico in the early 1900's but my soul, "mi alma", is Mexican.