'The improviser has to be like a man walking backwards. He sees where he has been but pays no attention to the future. His story can take him anywhere, but he must still 'balance' it, and give it shape, by remembering incidents that have been shelved and reincorporating them. Very often an audience will applaud when earlier material is brought back into the story. They couldn't tell you why they applaud but the reincorporation does give them pleasure.' Keith Johnstone, Impro