A lot of buildings, including hospitals, don’t have a 13th floor…

A lot of buildings, including hospitals, don’t have a 13th floor because so many people fear the number, which itself a condition called triskaidekaphobia. They include Napoleon and Franklin D. Roosevelt, who refused to travel on the 13th day of any month and would never host 13 guests at a meal. According to livescience.com, Mark Twain once was the 13th guest at a dinner party that a friend warned him to avoid. “It was bad luck,” Twain later told the friend. “They only had food for 12.” In fact, in Paris, the site says, superstitious diners “can hire a quatorzieme, or professional 14th guest.”