From Roger Ebert:
In 1979, Burns told me: "I was acting when I was 2. When I was 7, I was in the Pee Wee Quartet." Then he told me a story about another old-timer:
"There was a guy, a tramp comedian named Joe Jackson. He was famous for how he handled the curtain. He had these big, floppy shoes, and he'd stand onstage just where the curtain fell, so his toes would be sticking out under the curtain. So the audience knows he's still there. They go crazy, applauding. Meanwhile, Jackson slips out of the shoes. He waits until the applause is dying down, and then he steps out from the side of the stage in his stocking feet. That brought the house down.
"One night, the curtain comes down. Jackson steps out of his shoes. Then he dies backstage. Drops dead. The audience knows the gag, see, and so they're cheering, applauding ... the greatest ovation Joe Jackson ever got, and he didn't live to hear it.
"When I tell that story, people sometimes burst into tears. I hate to break the news to them that I made it up."