An actor had been out of work for 15 years because he always forgot his lines. Then one day he got a phone call from a director who wanted him for a big part in a play. All he had to say was "Hark! I hear the cannon roar!"
After much worry the actor decided to take the role. Opening night arrived, and while he waited in the wings, the actor muttered to himself "Hark! I hear the cannon roar! Hark! I hear the cannon roar!"
The time for the entrance finally came and as the actor made his appearance, he heard a loud brooooom! He turned around and said, "what was that?"