"Someone said, 'Great, you're the Facebook guy!' And he was so embarrassed," says Reznick, now a medical student at Case Western Reserve University in Cleveland. "He really played it down."
Classmate James Oliver recalls a conversation in the dorm soon after, when Zuckerberg — he and others still refer to him as "Zuck" — explained that he had worked to launch Facebook quickly to show up a Harvard administrator who had said a university-wide online directory would take two years to create. By the end of the semester, Facebook had nearly 160,000 users.
But three fellow Harvard students quickly took issue with Zuckerberg's creation. Identical twins Cameron and Tyler Winklevoss and friend Divya Narendra said they had hired Zuckerberg to write computer code for their own social networking site in November 2003, and that he had stolen their idea.
The dispute over Facebook's beginnings — which the company settled by paying the trio $65 million — is far from unique.
"Being first is heavily overrated in the technology space because all really good ideas end up being collaborative. ... It's the execution that matters," said Paul Saffo, of the San Francisco analysis firm Discern.
In the summer after his sophomore year, Zuckerberg left Harvard for a rented house in Silicon Valley to build Facebook, expanding it to other campuses and then across the globe with venture funding from Peter Thiel, one of the founders of PayPal. Each time it seemed to plateau, Zuckerberg revamped it to create new utility and sources of entertainment. He turned down an offer from Yahoo! to buy the company for $1 billion.
As it has grown into a phenomenon, Facebook has repeatedly sparked privacy concerns from critics concerned about its push to get users to reveal more personal information. But Zuckerberg, the face of Facebook, has offered up relatively little about himself.
The bubble was breached in 2007 when 02138, a now defunct magazine for Harvard alumni, published a lengthy story about the dispute over Facebook's beginnings. The magazine obtained court files that were supposed to be sealed and posted documents on its website, including Zuckerberg's application to Harvard and long-ago postings from his online journal. Richard Bradley, the executive editor of the magazine, said the documents revealed details including Zuckerberg's social security number and financial data from Facebook's first year.
Facebook sued, seeking a court order to have the documents removed.
"They shed some insight into Zuckerberg which he clearly did not want people to see," Bradley said. "Our lawyer conveyed to us the strong sense from his communication with Facebook's law firm that Facebook's lawyers were not entirely enthusiastic about pursuing this litigation, but that Zuckerberg himself was livid."
Facebook's request was denied and the documents circulated freely on the Web, with little other information available to counter the portrait of Zuckerberg they offered. Some of those who know him say the perceptions are misguided. Rather than being some kind of anti-social genius, his success was based on the fact that he liked people and was well liked, they say.
Kirkpatrick, who wrote the book on Facebook, said Zuckerberg's true genius is understanding how, in a new age, people and computers can interact.
"Zuckerberg thought, 'I want to take the fact that transparency and sharing are the future," he said, "and build technology that takes that for granted.'"