Billy Crystal's Tony-winning 700 Sundays is one of the hottest tickets in town! The legendary comedian's fans are traveling from near and far to catch the solo show, which might explain why some of them are nodding off while Crystal pours his heart out on stage. On December 11, Crystal swung by The Late Show with David Letterman to jokingly lament about the "heroin addicts on a field trip" who are falling asleep in the front row. However, the funnyman was forgiving enough to admit that he's also a theater nodder. "I saw The Book of Morm—I did not see the whole thing," he joked. Crystal also copped to almost falling asleep during James Earl Jones' performance in Fences. What stopped him? Find out in the clip below!