On October 18th, 1961, Henri Matisse's painting "Le Bateau" (The Boat) was hung in the Museum of Modern Art (MOMA) in New York. On December 4th (forty-seven days later) it was briefly taken down. Why? The artist's son noticed that the painting had been hung upside down!

["Matisse coined the name Cubism as a derisive joke. He initially hated the aggressively drab new style, which incidentally torpedoed his leadership of the avant-garde. In 1908, according to Picasso's mistress Fernande Olivier, Matisse 'lost his temper and talked of getting even with Picasso, of making him beg for mercy.'" (New Yorker, 2003-03-03)]