Sir Ian McKellen returned a £1 million (NZ$2.08 mill) memoir advance because he found writing it "painful".
The Lord of the Rings: The Fellowship of the Ring star had signed a deal with publisher Hodder & Stoughton to release a book about his life but changed his mind because he didn't want to "go back and imagine things that I hadn't understood so far".
Speaking at the Oxford Literary Festival, he said: "I put nine months aside to do it, and I got a very handsome advance. Then I sent the money back.
"It was a bit painful. I didn't want to go back into my life and imagine things that I hadn't understood so far. The privacy of my life I don't quite understand myself, and it has nothing to do with what I do for a living. So there you go, I'm sorry."
Meanwhile, the 76-year-old actor previously revealed he finds fame quite "comforting" because he's generally quite a shy person.
He said: "As someone who started out life pretty shy, and who is still pretty shy, it's very comforting to be known.
"You'll walk into a room, some people come up and say hello and tell you why they're saying hello, because they liked a play or a film and I know where I am."
- Bang! Showbiz