“Otherwise,” he asked rhetorically, “what have I learned?” During his PayPal days, Levchin was so committed to seeing the company succeed that he often sacked out at the office in a sleeping bag he kept under his desk. Considering that he described his apartment during some of this time as “scary,” that had a certain logic. Cardboard boxes served as his living room furniture; a discarded computer desk was his dining room table. These days, despite the phenomenal success of PayPal, which gave him the bulk of a fortune worth around $100 million, Levchin continues to work an average of 15 to 18 hours a day. “We occasionally go out to eat, he sleeps a few hours, he works out,” Minkova said. “But other than that, Max works.” Minkova half-joked that she might appreciate her occasional evenings out with Levchin more, if only he were not on his BlackBerry, answering e-mail messages and checking his Web site. One friend, Dennis Fong, who sold a company to MTV Networks last year for $102 million (and is already at work on a new startup), talks about the “weird growling sound” that Levchin tends to make when someone even mentions the name of his chief rival, RockYou. And so committed is Levchin to seeing Slide.com succeed that he keeps a blood-pressure monitor on his desk. “I don’t know what I would do if I couldn’t start companies,” he said. “I’d probably think about slitting my wrists.” 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! AD Quality Auto 360p 720p 1080p Top articles1/5READ MOREGame Center: Chargers at Kansas City Chiefs, Sunday, 10 a.m.Levchin, who is now 32, is typical of a new generation of junior titans in Silicon Valley who might be called the prematurely rich – techies worth tens of millions of dollars, sometimes more, at an age when many others are just starting to figure out what to do with their lives. The Internet, a low-overhead medium with a global reach, has greatly accelerated the wealth creation phenomenon, producing a larger breed of multimillionaires even younger and richer than in the past. They are happy to be wealthy, of course, but many of these baby-faced technology tycoons often seem indifferent to the buying power of their money, at least at this stage of their lives. Instead, nearly all of them have chosen to throw themselves back into a startup, not so much because they want a spectacular new home or a personal jet – though many of them do – but because they are in a competition with themselves and one another. “For most of us, doing it again means surpassing what we’ve done previously,” said Peter A. Thiel, Levchin’s partner at PayPal, who also has started a new business, a hedge fund called Clarium Capital. “And that can be a really high bar.” Even among this jittery group of overachievers, Levchin stands out. In part that is because outdoing PayPal may be an all-but-impossible goal. Levchin acknowledges that he has already earned more money than he could ever spend. But he said he would not consider Slide.com, the photo and video sharing site he founded in 2005 that is still in its startup phase, a success unless it is ultimately worth, in real dollars, “at least $1.54 billion” – the price eBay paid for PayPal. SAN FRANCISCO – Max Levchin is not easily distracted from his work. A few years ago, Levchin, one of the young princes of Silicon Valley, bought his first home, a 12-room Edwardian high atop a hill here, for $3.4 million. But Levchin, who made a fortune at age 27 selling PayPal, the online payment service he helped start in 1998, never moved in. He sold it two years later without having slept there for even one night. Since then, Levchin has moved into his second home, a more expensive one found for him by Nellie Minkova, his girlfriend of eight years who has become his fiancee. But so consumed is he by work on his second company, an Internet startup focused on sharing photos and videos, that the cartons that contain what Levchin described as “85 percent of my worldly possessions” are still stacked in his living room, five months after moving day.