“No matter how hard it looks, it’s harder than it looks.”

Ben Horowitz, founder and general partner of the venture capital firm Andreessen Horowitz, set the tone for Saturday’s Startup School, a symposium run by YCombinator, a startup incubator, and the Business Association of Stanford Entrepreneurial Students (BASES). He joined Mark Zuckerberg and a number of prominent Silicon Valley figures who discussed their experiences with founding and growing startup companies.

Startup School admitted 1,800 attendees, covering a range of professional and nonprofessional levels, after an application process that ended in September.

“We used to have around 900 attendees come to Dinkelspiel Auditorium, and this year we were able to accommodate about 1,900,” said Ruby Lee ’13, co-president of BASES.

“The draw isn’t just the talks”, said Dean Cooney, a sophomore at the University of Chicago, who flew in for the event. “It’s more the people who come here. People come from all over — in fact, I noticed more people who came in from elsewhere, instead of people from California.”

Mark Zuckerberg kicked off the event with a discussion of his experiences during the early startup phases of Facebook. His talk was moderated by Phil Graham, a YCombinator founder. Zuckerberg’s talk was greeted by raucous applause and was often punctuated by claps or laughs from the audience.

“It was really hard to decide to start a company,” he admitted. He said that while he felt that there was space for a new social network in the market, at the time of Facebook’s founding, he doubted his own abilities.

“I thought it would be someone big like Microsoft,” he said, discussing his surprise with Facebook’s popularity and growth in the social network sphere.

Zuckerberg also emphasized the need to develop something that is unique and that can present a clear alternative to the competition. He substantiated it with an anecdote from his early days of expanding and growing Facebook in new markets.

“Some schools would take longer than others,” he said. “So we wanted to go to the schools that would be the hardest for us to succeed at.”

His rationale was that by entering markets where it would be most difficult to succeed, he would know through success or failure whether he had a product that was truly special. He went on to admit his own naiveté at the time of Facebook’s creation.

“I never really understood the psychology of starting a company,” he said.

Later in the day, Travis Kalanick, founder and CEO of Uber, a luxury-vehicle hire company, added to the day’s theme of disruption and pioneering new fields.

“When you do something successful, not everybody is happy — the older the industry you’re attacking is, the more it is protected.”

Kalanick added that having a unique solution to a unique problem is what really matters in the startup world.

If there was one consistent theme running through every speaker’s talk, it was the difficulty of executing an idea unique enough for people to want, and eventually to need.

Horowitz explained that from the point of view of venture capitalists, “A breakthrough idea is something people can’t see at first.”

“All great investments look controversial at the time; a startup founder needs the courage to have a breakthrough idea,” he said.

He argued that the key is to make something that people first want, and then slowly need, to use.

“Come on, you all need Facebook,” he joked, referring to the social network’s increasing global popularity.

Horowitz went on to stress the importance of management in the slow transition from a startup to a full-scale company.

While Horowitz acknowledged that the founders’ technical skills are the basis for the establishment of any company, he said the ability to “articulate a vision that can get people to follow you” is key to its growth.

Jessica Livingston, partner at YCombinator, had emphasized similar ideas earlier during the event, explaining the importance of dedication in the success of any entrepreneurial initiative.

“If you execute well, then eventually you will win people over…While the process is like a roller coaster, startups are hard, not impossible,” he said.

“The product is the only thing that matters, and everything you add makes everything else less important,” said Tom Preston-Warner, CEO of Github. “If you can argue about something that matters, and not the people behind it, you can have a good product…and throw all your titles away.”