"What I can't deny is my yearning. I'm definitely still wild at heart but I've struck biogravity. I have had everything a man could ask for but no one could say I'm successful with affairs of the heart.
"I don't think relationships are fixed things. People are necessarily complex and confused beings. We don't always do the right thing, say the right thing and behave the way we always want to behave."
Now Nicholson admits his dating days are over, and he prefers to stay in and watch a film.
A source added: "He's afraid of dying alone in that house," referring to his mansion that his children want him to sell.
"They've been encouraging him to downsize and move into a more manageable place in Beverly Hills. But he loves his old place in the Hollywood Hills."
Nicholson spoke about his stormy, decades-long affair with Anjelica Huston and said their break-up was "the toughest period of my life".
They met in 1973 at a party at his house in Los Angeles and Huston has said she fell in love at first sight.
Their relationship would last until 1989, even though he repeatedly cheated on her. The final straw was when he told her he had got actress Rebecca Broussard pregnant. He went on to have two children with her.
In her memoir, released last year, Huston described how she beat Nicholson brutally about the head when he flippantly told her over dinner: "Someone is gonna have a baby."
Nicholson said: "I was annihilated emotionally, that was probably the toughest period of my life. I'm childish and I did make a mistake."
Huston said Nicholson was the "love of my life" but admitted she was "tragically gullible" towards his "charm offensive".
Nicholson was married to Sandra Knight between 1962 and 1968 and the couple had a daughter, Jennifer, now 52. Miss Knight told Closer: "We had a very beautiful, sweet marriage. I could see Jack was going to become a big star and have lots of temptations. I couldn't go along for the ride. He's different from the Jack Nicholson image. The real Jack is a loving, caring, giving person."
