Okay, America, it's time for a history lesson. Who shot Abraham Lincoln? While 75 percent of the 1,218 adults surveyed in 60 Minutes/Vanity Fair poll answered correctly with the name of actor John Wilkes Booth, 7 percent went for that other three-named presidential assassin Lee Harvey Oswald, who we all should remember shot John F. Kennedy. At least only 1 percent thought that Michael Tilson Thomas, a living and (as far as we know) unthreatening conductor and composer, was the assassin. So perhaps a refresher course on U.S. history is needed for some people — or perhaps just a greater appreciation of the work of Stephen Sondheim