My sisters told me when I was 5 years old - I think.... My DD teaches 4th & 5th grade, she is not sure each year who still believes and who does not, so she has to walk on eggshells each year because she does not want to be the one that bursts the bubble. One of her students was a little girl adopted from China that had a melt down when she found out she couldn't be president because she wasn't born here. My DD didn't realize her student had that dream.