Mark Zuckerberg, who famously dropped out of Harvard College to start a little website called Facebook, will be back there on Monday to recruit some of its computer scientists to his now-giant firm. The university said Zuckerberg, now 27 and often cited as America's youngest billionaire, will be at a session next week with 200 computer science students. He was once one of them -- he would have graduated in 2007 -- and he now wants their help to run Facebook for its 800 million worldwide members. "It is Zuckerberg's first official visit to Harvard since leaving in 2004 to launch Facebook," said the university in a statement. Where to Start a Company? At a forum in California over the weekend, Zuckerberg said in passing that if he had it to do over, he might still be in the Boston area. It might have been a better place than Silicon Valley to run Facebook as a firm. "If I were starting now,'' he said, "I would do it very differently, but I knew nothing back then. Honestly, if I were starting now I would have just stayed in Boston." Silicon Valley, he said, is a lively place -- one of the few places where things are going right for the American economy -- and it was the right place at the time to start Facebook. But it is "a little short-term focused, and that bothers me," he said. "A lot of the companies that have been built outside of Silicon Valley ... seem to be on a longer-term cadence than the ones in Silicon Valley.'' "One of the things that worries me is that there's this culture out here in the Valley of people going to start companies before they know what they want to do," said Zuckerberg. "You've decided you want to start a company, but you don't know what you're passionate about yet." Zuckerberg, speaking rapidly and easily at the Y Combinator's Startup School at Stanford University, said he and his cohorts fully admitted they didn't know what they were doing when they started Facebook. "We didn't expect this thing to be a company initially. We just built it because we thought it was awesome."