I didn't end up getting kicked out -- I did that to myself. Priscilla and I started dating. And, you know, that movie made it seem like Facemash was so important to creating Facebook. It wasn't. But without Facemash I wouldn't have met Priscilla, and she's the most important person in my life, so you could say it was the most important thing I built in my time here.

We've all started lifelong friendships here, and some of us even families. That's why I'm so grateful to this place. Thanks, Harvard.

Today I want to talk about purpose. But I'm not here to give you the standard commencement about finding your purpose. We're millennials. We'll try to do that instinctively. Instead, I'm here to tell you finding your purpose isn't enough. The challenge for our generation is creating a world where everyone has a sense of purpose.

One of my favorite stories is when John F Kennedy visited the NASA space center, he saw a janitor carrying a broom and he walked over and asked what he was doing. The janitor responded: "Mr. President, I'm helping put a man on the moon".

Purpose is that sense that we are part of something bigger than ourselves, that we are needed, that we have something better ahead to work for. Purpose is what creates true happiness.

You're graduating at a time when this is especially important. 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.

As I've traveled around, I've sat with children in juvenile detention and opioid addicts, who told me their lives could have turned out differently if they just had something to do, an after school program or somewhere to go. I've met factory workers who know their old jobs aren't coming back and are trying to find their place.

To keep our society moving forward, we have a generational challenge -- to not only create new jobs, but create a renewed sense of purpose.

I remember the night I launched Facebook from my little dorm in Kirkland House. I went to Noch's with my friend KX. I remember telling him I was excited to connect the Harvard community, but one day someone would connect the whole world.

The thing is, it never even occurred to me that someone might be us. We were just college kids. We didn't know anything about that. There were all these big technology companies with resources. I just assumed one of them would do it. But this idea was so clear to us -- that all people want to connect. So we just kept moving forward, day by day.

I know a lot of you will have your own stories just like this. A change in the world that seems so clear you're sure someone else will do it. But they won't. You will.

But it's not enough to have purpose yourself. You have to create a sense of purpose for others.

I found that out the hard way. You see, my hope was never to build a company, but to make an impact. And as all these people started joining us, I just assumed that's what they cared about too, so I never explained what I hoped we'd build.

A couple years in, some big companies wanted to buy us. I didn't want to sell. I wanted to see if we could connect more people. We were building the first News Feed, and I thought if we could just launch this, it could change how we learn about the world.

Nearly everyone else wanted to sell. Without a sense of higher purpose, this was the startup dream come true. It tore our company apart. After one tense argument, an advisor told me if I didn't agree to sell, I would regret the decision for the rest of my life. Relationships were so frayed that within a year or so every single person on the management team was gone.

That was my hardest time leading Facebook. I believed in what we were doing, but I felt alone. And worse, it was my fault. I wondered if I was just wrong, an imposter, a 22 year-old kid who had no idea how the world worked.

Now, years later, I understand that *is* how things work with no sense of higher purpose. It's up to us to create it so we can all keep moving forward together.

Today I want to talk about three ways to create a world where everyone has a sense of purpose: by taking on big meaningful projects together, by redefining equality so everyone has the freedom to pursue purpose, and by building community across the world.

First, let's take on big meaningful projects.

Our generation will have to deal with tens of millions of jobs replaced by automation like self-driving cars and trucks. But we have the potential to do so much more together.

Every generation has its defining works. More than 300,000 people worked to put a man on the moon – including that janitor. Millions of volunteers immunized children around the world against polio. Millions of more people built the Hoover dam and other great projects.

These projects didn't just provide purpose for the people doing those jobs, they gave our whole country a sense of pride that we could do great things.

Now it's our turn to do great things. I know, you're probably thinking: I don't know how to build a dam, or get a million people involved in anything.

But let me tell you a secret: no one does when they begin. Ideas don't come out fully formed. They only become clear as you work on them. You just have to get started.

If I had to understand everything about connecting people before I began, I never would have started Facebook.