Michelle Obama arrived in Washington this morning after she left Europe early to be home in time to start Sasha and Malia's school week. Overall, her first European tour was a success, with the exception of that fateful hug with the queen. Though Buckingham Palace said the first lady did not err because the only rule is to be polite, respectful, and courteous, it's, of course, just being polite. There are rules — old-fashioned and unspoken, but rules nonetheless. Think you'd know what to do? Find out with my quiz.