In this 1983 episode of PM Magazine, Maria Shriver interviews Mark Hamill before the release of Return of The Jedi and asks him why there is
so much secrecy around this film as well as if it's true that he will star as Luke Skywalker 18 years into the future.
"2004 or something. But he's(George Lucas) being very cagey about it. He says it may take place in another plane of existence or will not be the same kind of character. I can't really explain why without getting into sensitive material."