(FORTUNE Small Business) – I'm in Paradise Valley, Ariz., riding shotgun with Robert Kiyosaki, best-selling author of Rich Dad, Poor Dad: What the Rich Teach Their Kids About Money That the Poor and Middle Class Do Not! We're on our way to lunch at Kiyosaki's favorite restaurant, Lon's at the Hermosa. Kiyosaki has chosen the black Porsche today; the white Porsche and the Bentley are back home in the garage. "You know the difference between a porcupine and a Porsche?" Kiyosaki asks, looking at me sideways. "With a porcupine, the pricks are on the outside." Kiyosaki chuckles. "I had to overcome that stigma."

Kiyosaki has had to overcome many stigmas in his 57 years. The stigma of being an averagely well-off kid in a Honolulu school full of rich kids—which is how he came to devote his life, from age 9, to uncovering the secrets of wealth. The stigma, in the eyes of his late father—a third-generation Japanese immigrant, public school superintendent, and Peace Corps administrator, and the model for Poor Dad—of taking a job in sales. ("I might as well have said I was going to be a pedophile.") And the stigma, after hitting it big in the wallet business, of being publicly branded an entrepreneur. His father phoned him, aghast: "You see what they called you in the paper?" The shame!

Poor Dad's attitude softened with time. Still, Kiyosaki waited until six years after his father's death to publish Rich Dad. "Because if I shared it with him earlier, he would have died that day," he says. Rich Dad tells the story of young Robert's apprenticeship under the father of his best friend, Mike, a savvy entrepreneur whose mantra was "I don't work for money! Money works for me!" An eager student, Kiyosaki went on to launch several businesses, invest aggressively in income-producing real estate, and "retire" while still in his 40s on a portfolio that he says was throwing off $10,000 a month.

Kiyosaki's message, on which he elaborates while sipping iced tea at Lon's, comes down to this: "If you can't get rich in this country, hang 'em up!" Rich Dad tries to show you how, using a mix of psychobromides ("It's easier to change yourself than everyone else"), financial common sense ("You must know the difference between a liability and an asset, and buy assets"), and iconoclastic zingers ("This pattern of treating your home as an investment ... is the foundation of today's debt-ridden society").

Note that Kiyosaki did not begin to accumulate true riches—I'm talking about Bentley bucks now—until he got into the business of teaching other people how it is done. Rich Dad was self-published in 1997; it was a $15.95 "brochure," as Kiyosaki calls it, originally designed to attract customers to his website, where he could sell them Cashflow, his $195 board game. It wasn't until 2000, when Oprah had Kiyosaki on her show and Warner Books (a division of FSB's corporate parent) picked up the rights to Rich Dad and the spinoffs that followed, that Kiyosaki started rolling in it. "We're approaching $1 billion at retail worldwide," he says. "I've sold 25 million copies of my books, 350,000 games. Running it with 20 people, no debt, and 70% margins." He's grinning now, widely.

After lunch we stand in Kiyosaki's brick-paved driveway, talking about rental real estate, still his favorite investment vehicle. "Right now it's really hard to put a deal together because every amateur in the world is in it," he says, regretfully. So does he fear a crash? I ask. "I hope it crashes," he says. "Every night I light candles and pray to the god of real estate crashing, and I say, Please! One more crash! Let it go down so I can get back in there again!"

Later I call him. I've been wondering, What about his readers? The ones who are taking his advice and jumping into real estate at exactly the wrong time? "I'm a professional," Kiyosaki coolly explains. "I make money when the market is up, and I make money when the market is down." He pauses. "Now can they do that? That's another story."