By Juju Chang and Chris Murphey:

Rod Stewart is no longer a young Turk, but he's still selling out shows with his raspy voice, just as he did back in the '80s after he took that detour to disco. Who could forget "Da Ya Think I'm Sexy?"

But it's Stewart as a crooner taking on the American songbook that's catapulted him into becoming one of the best-selling musicians of all time - and a headliner at Caesars Palace.

So what's propelled Stewart through five decades of success? He says he is a man driven by his many obsessions.

Take that famous head of hair, for instance.

"There's good days and there's bad days, and it's been like this off and on for 40-odd years," he said.

How did he first get the look?

"Those were the days before hair lacquer," Stewart said. "Sugar and warm water, and rub it in there. And then it sticks up, erect, you know."

Speaking of which, Stewart has pursued the ladies obsessively, too, romancing some of the most beautiful women in the world, including Britt Eklund and Alana Stewart.

What makes him so attractive?

"It beats me to this day, I must admit," Stewart said. "I look at myself in the mirror every morning, and I look an absolute shambles. And I did back then, as well. … Maybe it's because rock 'n' roll is so connected to sex. … It's a position of power, I suppose."

Stewart comes clean about his obsessive skirt-chasing in his intimate new memoir, "Rod: The Autobiography." He also shares the pain he felt when his second wife, Rachel Hunter, left him.

The book sets the record straight on other points, too. Contrary to popular belief, Stewart never played professional soccer; he merely tried out. He was never a grave digger, though he did work at a cemetery. The biggest myth Rod wants to dispel is the urban legend about getting his stomach pumped after reportedly ingesting a bodily fluid.

"I had a very mean-spirited press man that is no longer on this earth, so there's not much he can do about it. But he was upset at being fired, so he decided to start this ridiculous rumor. 'Spiteful' is the word I would use," Stewart said with a laugh.

"And my kids had to live with this for a while," he added. "You know, it's hard. It's a wicked, wicked thing."

Stewart pursues everything in life with a singular passion - including model railroads. Far from merely playing with trains, Stewart paints landscapes and creates replicas of cities. His miniature landscape spans 125 feet and re-creates Grand Central Terminal in postwar New York. It's a work of art.

"I am a man of contradictions, I suppose. I mean, how many rock 'n' roll stars have a hobby of model railroads?" Stewart asked, adding that the hobby is an escape. "I get up to the top of the house here, and the whole world can go f-k itself, for lack of a better expression. It clears my head, you know?"

Stewart's talent has made him wealthy beyond his wildest dreams growing up as the son of a plumber in working-class North London. He wrote songs that drew on his life experiences, such as losing his virginity to an older, "slightly portly" woman. That event became "Maggie May."

Now 67, Stewart said he's a changed man. He's married again - for the third time - to former model Penny Lancaster.

"Rod was very honest and said, 'Look, I've been through a few marriages. I've got kids, and I can't see myself doing that again,'" Lancaster said. "But we were in love and we wanted to be together. [Then] one day, Rod said to me, 'Let's make a baby,' just out of the blue."

They have two sons: Aiden, 18 months, and Alastair, 7.

Family has always been one of Stewart's biggest obsessions, and his two young boys keep him on his toes.

He's got two kids. He's writing songs again. He's had more success in the past decade than in his entire career before that. How does Stewart explain it?

"I'm one hell of a lucky guy, that's for sure."