"I put nine months aside to do it, and I got a very handsome advance," he said. "Then I sent the money back."
The Times reports him as saying: "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. Frankly, if anybody wants to know anything about my public life, my working life, my career, it's all catalogued in greater detail on my website than could ever be put into a book."
McKellen implied he wasn't comfortable with disclosing details from his private life in the book.
"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."
He also spoke about his first love, whom he claimed he met while acting in Oxford at the beginning of his career.
"It was actually in this town that I was acting with some undergraduates and I fell in love with one of them," he revealed. "So Oxford is a very special place for me. It was the first person I felt attached to in that way." Speaking to Owen Jones just last month, McKellen did speak about his experience of growing up gay. He said he was “deeply closeted, unable to talk to my parents about it." The much loved Shakespearean actor first came out publicly in 1988.More stories Ian McKellen: MP told me Section 28 was Thatcher's bit of red meat for the right Ian McKellen says Hollywood snub extends to 'disregarded' gay actors