When Mia Thermopolis learned that her grandmother was actually Queen of Genovia, it was, naturally, a huge surprise. After all, she was just a normal San Francisco teen before she got the news.While that's, of course, the plot of the movie The Princess Diaries and not, um, real life, we always assumed that such a revelation would be a bit different for the members of Britain's royal family. After all, they must grow up with knowledge of their status. Well, apparently not.In an interview with the BBC Sophie, Countess of Wessex said that her daughter Lady Louise got a "shock to the system" when she learned her grandmother was the Queen. Sophie is married to Elizabeth II's son Prince Edward, making Lady Louise the granddaughter of Her Royal Highness. But according to Sophie, Louise only got wind of her grandmother's title when people at school brought up the subject."I asked her, 'Yes, how does that make you feel?' And she said, 'I don't understand,'" Sophie explained. "I don't think she had grasped that perhaps there was only one queen."Lady Louise may have now come to grips with the fact that she is far from a normal British citizen, but at least she can take comfort in knowing that she does have something in common with the rest of us: a mother who won't hesistate to embarrass her in public.