Being able to critique yourself is a good skill. Often when a film has been released I’ll ask: “Did I make mistakes?” When I made The Cotton Club in 1984, people were telling me there were too many black people in it and too much tap dancing. I would say: “But it’s a movie about black people tap dancing.” Years later, I realised I had taken out half of the backstory. It was good to go back and fix that. Life is a great screenwriter. My daughter, Sofia, got such awful, unjust criticism for her performance in The Godfather Part III. She was 18 and was being told she’d ruined her father’s film. It was a deep wound for the poor kid. They were gunning for me, but she took the bullets. Now she is a more famous movie director than me. She got the last laugh! I don’t always want to tinker with movies, only when I’ve had annoyances. I’m lucky enough to own some of the movies I’ve made, so why not? Me and The Godfather are done now. There is more that [screenwriter] Mario Puzo wrote that we never used. But I don’t own The Godfather, Paramount owns The Godfather, and they may well decide to make more films. I feel that I’ve made my trilogy. I have other fish to fry. Releasing a movie is like following a sports team. You always sigh. Relief always follows the release of a movie, even if it’s a feeling of despondency. Film is an illusion. The audience just sees a lot of shadows on the screen. The emotion is in the audience. The trick is giving them something that unleashes that and suddenly they endow the images with their emotion. My theory is, when people say a movie is beautiful, I don’t think it can be unless there is beauty in the audience. Little matters more to me than the environment. We have to save the Earth. But the climate issue isn’t strictly about the Earth. Earth is going to survive, it’s been through many ice ages. It’s about the human race. I think we’re worth saving. We need to see each other as family. You and I are relatives. You go way back to your first grandmother and mine is the same woman. All humans living today are blood relatives, and therefore we must embrace each other and work with each other and lift each other up. Because we’re family. We’re the human family. I want to make a film about the future. You know the Alfred, Lord Tennyson quote? “For I dipt into the future, far as human eye could see, saw the vision of the world, and all the wonder that would be…” That’s the movie I want to make. It would be called Megalopolis. I’m 81 so I hope I have enough years to make it. I want to give the children of the world a vision of the future that is beautiful. That is positive. That is a heaven on Earth, because I really think we can have that. Mario Puzo’s The Godfather Coda: The Death of Michael Corleone is in cinemas now and on Blu-ray from 8 December