Mark Zuckerberg finally has his Harvard degree. The Facebook CEO and famous college dropout left the Ivy League university 12 years ago to found the social network, but he returned Thursday to pick up a honorary doctor of laws degree and drop some wisdom on the class of 2017.

In prepared remarks provided to The Washington Post ahead of the speech, Zuckerberg called on his alma mater's newest graduates to tackle major, ambitious "public works" projects that bring together masses of people for the general benefit of society. He noted that many technologies - including some being developed at Facebook - are changing the world and also presenting new challenges.

"You're graduating at a time when this is especially important," Zuckerberg said in the prepared remarks. "When our parents graduated, purpose reliably came from your job, your church, your community. But today, technology and automation are eliminating many jobs. Membership in communities is declining. Many people feel disconnected and depressed, and are trying to fill a void."

Zuckerberg, 33, is the youngest person to deliver a Harvard commencement speech, according to Facebook - a fact that he wanted to highlight to the crowd. "We walked this yard less than a decade apart, studied the same ideas and slept through the same lectures," his speech said. "We may have taken different paths to get here, but today I want to share what I've learned about our generation and the world we're building together."

Some of Zuckerberg's remarks echo the manifesto he published earlier this year, outlining how he saw Facebook's mission as establishing a "social infrastructure" for the world. But the central theme of Zuckerberg's address was to call on young people to create a world where "everyone has a sense of purpose" by looking beyond their own needs.

"I'm not here to give you the standard commencement about finding your purpose," the speech said "We're millennials. We'll try to do that instinctively. Instead, I'm here to tell you finding your purpose isn't enough."

Noting that society will likely see "tens of millions of jobs replaced by automation like self-driving cars and trucks" in the coming years, Zuckerberg called for young people to work on large public works projects to make new jobs. Though he didn't specify what sorts of projects those should be, or what hand companies such as Facebook could play in them, he did cite some past examples.

Zuckerberg noted that previous generations have their own "defining works" - the Hoover Dam, the space program, the fight against polio - that pulled them together and imbued America with civic pride. Citing global problems including climate change and pandemics, Zuckerberg said that millennials, himself included, understand themselves as global citizens rather than belonging to any nation-state.

"To keep our society moving forward, we have a generational challenge - to not only create new jobs, but create a renewed sense of purpose," he said. "So what are we waiting for? It's time for our generation-defining public works. Let's do big things, not only to create progress, but to create purpose."