Elton John pins his hopes on love
He has sold a quarter of a billion records worldwide. He has recorded the biggest selling single of all time. He has won six Grammy Awards, four Brits and an Oscar.
But, at the age of 66, Sir Elton John is starting to feel the irresistible pull of parenthood.
"While I'm feeling good, I'm going to keep working," he says.
"When Zachary goes to school, that's another different thing."
"I want to take him to school and I want to pick him up. I don't want to miss that part of his childhood."
Sir Elton's son Zachary was born to a surrogate mother on Christmas Day 2010. There is no doubt his arrival has been a turning point in the turbulent life and career of one of music's most successful artists.
The singer always thought he was too old, too selfish, too set in his ways to have children.
"It proves you're never right all the time," he reflects. "I haven't loved a human being more than him, ever."
So much so, he says he would love to have another child. "When it's time, we probably will. I'm now the happiest I've ever been," he adds.
Quite a change for the man who used to throw a fit if he didn't like the curtains in his hotel room. But fatherhood has made Sir Elton reflect on his life and the world in a new light.
In his first book, Love is the Cure, Aids and HIV are the subjects that absorb him most.
"People are still ashamed and frightened to admit they are HIV positive."
"It's the stigma of being gay, because it's a sexually transmitted disease, mostly, or intravenous drug use."
"We're facing a really hard time when it comes to getting rid of the stigma. I think it's as bad now as it was thirty years ago."
As his book title suggests, Sir Elton believes love is the cure. He acknowledges people might think he is naive: Aids is a deadly disease, not something that can be wished away with sappy celebrity sentiments and positive thinking.
But he wants people to "be more compassionate to one another, more Christian towards one another, not so hateful to one another".
And if people showed more understanding and less fear, he believes Aids could be obliterated forever.
Nonetheless he acknowledges apathy is a big problem. And he should know. During the 1980s, when fear of Aids was at its height and a whole generation of gay men were dying, the star sat on the sidelines, doing nothing.
"I was a drug addict, I was a user of cocaine, alcohol and marijuana. I knew that people were dying of Aids, because I lost so many friends. But I didn't actually do anything. I was afraid to raise my voice because I was in a drug-fuelled haze."
He still feels guilty that he didn't do more. But after he cleaned up his act he became determined to make up for lost time. He established the Elton John Aids Foundation in 1992.
Sir Elton says his biggest achievement is "getting sober." Without that he wouldn't have help raised more than £175 million for HIV/Aids research - or met his partner David Furnish.
The pair entered into a civil partnership on the first day it became legal in Britain - 21st December 2005.
But although he wanted to be legally bound to the man he loves, the singer says he doesn't see the need to get married.
"I don't need the Church to ratify my relationship. We're very happy the way we are. "
But he adds: "If marriage happens then great, I'm not going to say no. It's a step to equality and there is obviously debate on both sides. But it certainly isn't going to ruin civilisation.
Outspoken as ever, he adds: "Heterosexual marriage has done more to ruin the idea of marriage than anything else."
Sitting in the library of his home in Windsor, Sir Elton is surrounded by the awards of a glittering career - there are sixteen Ivor Novello trophies on one side-table alone. He is rock royalty, one of that elite group of British musicians, like Sir Paul McCartney and The Rolling Stones, who can still pack out a stadium.
He says he's surprised "in a way" that his career has lasted as long as it has. "But you look at everybody whose careers lasted forty years, and they are all great live."
"Record sales will go up, they'll go down, they'll go down, they'll go up... But what keeps you afloat is your ability to entertain and communicate with an audience."
And Sir Elton has always been able to do that.
Not surprisingly, he doesn't have much time for television talent shows like the X Factor and The Voice.
"Television is not a good way to have a start of a career. It's a shortcut to fame and it's also a shortcut to disaster."
"When you win the X Factor you have a year until it's the next person, and then you get dropped."
"Will Young is probably the biggest talent that's come out of it all. But the others I fear for."
"Leona Lewis has had an OK career, but she doesn't play enough live dates, nor does Alexandra Burke. Olly Murs has done OK. But where are these people going to be in ten years?"
"The proof of the pudding is The Voice. The single didn't get into the top forty, they've cancelled the live tour."
"There's been enough of these programmes now. Saturation."
And the singer has one piece of advice for those with dreams of making it big in the music industry.
"The right way to go about it is by getting in the back of a van with your mates, playing live, getting all that experience."
"Then making a record."
Love is the Cure is published on Tuesday 17 July