Earlier this month, Reuters Money featured a story with advice on how to get on the road to Millionaire Row. But what if you’re in a hurry, like so many multi-tasking teens of the 21st Century? What if your goal is to make that million by the time you turn 21? Can it be done?

The answer is yes, if you take the fast lane as an entrepreneur on steroids — something common to the four millionaires we polled for this follow-up. Three made it to the seven-digit milestone by 21; the fourth reached it when he turned 24. Here, those wealthy whiz kids past and present share the secrets that contributed to the fortunes they made.

Seated in the conference room of his wealth management firm in San Ramon, Calif., Rich Arzaga breaks out a few tools to explain the investment advantages of oil and gas drilling programs. He’s got a fine-point pen and a sketch pad — but alas, no milkshake a la Daniel Day-Lewis in “There Will Be Blood.”

“This is not wildcatting,” says Arzaga, founder and CEO of Cornerstone Wealth Management and an adjunct professor in personal finance at the University of California at Berkeley. Lewis’ anti-hero in “Blood” swindles and snakes for oil wherever he can find it, whereas Arzaga (pictured) wants to discuss something much more civilized: qualified drilling programs that yield big tax savings for investors and, if you’re lucky, 10 or more years of financial returns.

Though he first attended the Hollywood Bowl more than 30 years ago, Ron Moormeister remembers well those Los Angeles Philharmonic concerts. His voice waxes rhapsodic as he recalls the lineup: Mandy Patinkin, Julie Andrews, a Tchaikovsky Spectacular complete with the bombastic 1812 Overture.

So when he hit it big in 1995 — selling his insurance brokerage firm at age 49 — he decided to help the orchestra and to get a tax benefit too. He used a  charitable remainder trust, or CRT, a creative strategy that allowed him to give away his money, yet still derive funds from it based on a mix of tax deductions and investment.

While some youngsters long to become rock stars or Hollywood heavyweights, others now gravitate towards another stripe of pop-cultural celebrity: the whiz kid who becomes a millionaire before age 21.

That’s not hard to fathom now, given the likes of Facebook’s Mark Zuckerberg and other tech hotshots. But for Susan Beacham — founder of Money Savvy Generation — steady strokes and ingrained habits set kids on the course to riches. And Beacham should know: She practices what she preaches with her two teenage daughters, Allison, 19, and Amanda, 17.