Steven Silverman doesn't miss the old days: Those restless nights when, deep in the throes of his latest poker binge, he slept on an air mattress on the floor of his 2,700-square-foot penthouse apartment in Bethesda.

He'd log on to a poker Web site before going to sleep and set his computer volume as high as it would go. He'd patiently wait for a "fish," poker parlance for weak players willing to play for big stakes. For Silverman, a top player in the tight-knit online poker world, fish were easy to spot. The second he heard the "ding" of someone who had taken the bait, he was ready to go.

He crushed fish.

After dropping out of college to pursue poker full-time in 2007, Silverman became one of the most feared players in online poker. He traveled the world winning deep-stacked pots -- a $106,000 prize in Costa Rica, $128,000 in Monte Carlo. In February 2009, he won the coveted first prize in an online "Full Tilt" tournament for $350,000. A few months later, he appeared on a poker reality show on cable TV. He had fans online devoted to his style. He also had been robbed at gunpoint.

These days, he's trying hard to be retired. He dotes on his Shiba Inu puppy, Kunu. He's stressed about his organic chemistry grades at the University of Maryland. He's dating a literature major at American University.

"I'm a lot happier being a real person, with a normal routine," he says about life now. But how "normal" can life be when you're 22 and you've already won -- and lost -- millions of dollars?

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Silverman is one of a crop of poker stars who came of age alongside the online gambling industry. In the past decade, the United States has become the world's biggest online gambling market. In 2009, U.S. online site operators racked up $1.4 billion in revenue.

Silverman had had a series of obsessions as a kid: Nintendo, skateboarding, the guitar. Then came cards.

In 2003, amateur poker player Chris Moneymaker won the World Series of Poker, becoming the first winner to have qualified online. Silverman, then 15 and a student at Richard Montgomery High School, was inspired. He asked his older brother to sign him up for a free online poker account, where he competed as "Zugwat."

After his parents went to sleep, "Zug" competed online, and before long, he'd turned a free $15 promotion into a bankroll that Silverman puts at $30,000.

After just over a semester as a math major at UM, Silverman dropped out in February 2007 to pursue poker, first at underground games in College Park. Twice, the games were robbed, leaving Silverman and the other players without pants. "It was scary," Silverman says, "but at the same time it was kind of cool."