Thank you, Bill, for that introduction, but more importantly, thank you and Melinda for your tireless efforts towards making a better world. I’ve been reading about these Goalkeepers — you guys are pretty inspirational, and I am excited to be here with you. Whether it’s girls’ education, or global health, or climate change, you’re setting a standard for the sorts of innovation, persistence and activism that the world desperately needs right now, so I could not be prouder.

That’s really what I’m going to talk about very briefly before I have a chance for a discussion with Bill and Melinda; I want to talk about changing the world.

I remember sitting down with Bill in Paris a couple years ago, where the world was coming together to hammer out an agreement — a small agreement to save the planet — by taking meaningful action to tackle climate change. It’s a threat that may define the contours of this century more than just about anything else. Here was the interesting thing, Bill saw this not simply as a challenge, but as an opportunity. I remember him in sort of a matter of fact way saying, “Well, we’re going to just have to go ahead and invent some new technologies.” Which I said, “I agree, let’s do that,” although he knows more than me about inventing new technologies. But his tone was, “Yes, this is hard, but we can figure it out.“ It’s hard but, it can be done. And that spirit, the spirit that says, to quote I guess myself, “Yes we can,” rather than despair, is the motor by which we’ve been able to see real progress in reducing the pace of carbon emissions increases here in the U.S. And even if at the current moment the federal government is not as engaged in these efforts as I would like, nevertheless progress continues because of the efforts of people like Bill, and a whole host of entrepreneurs, and universities, and cities, and states. They are making change around energy policy in America separate and apart from what government is doing and that gives confidence that we can continue to make progress.

My broader point here is that, you tend to believe when Bill says that we can do something, that we can do it. And when all of you stand up and say this is something we can do, that kind spirit is infectious. And it’s exactly what we need right now.

We do face extraordinary challenges. You’ve heard of many of them in your discussions today. You know the nature of these challenges from your work. Growing economic inequality. A changing climate. Terrorism. Mass migration. Still too much extreme poverty. Still too many girls who are denied an education. The rise of nationalism and xenophobia. And a politics that says it’s not “we,” but “us” and “them” – a politics that threatens to turn good people away from the kind of collective action that has always driven human progress.

These are real challenges and we can’t sugarcoat them. They’re going to take a long time to solve. But that can’t discourage any of us from the belief that individually and collectively we can make a difference. We can make things better. And rather than be daunted by those challenge, those challenges should inspire us and excite us because it gives us an opportunity to make our mark on the world in ways that we haven’t even yet scratched the surface of. We have to reject the notion that we’re suddenly gripped by forces that we cannot control. We’ve got to embrace the longer and more optimistic view of history and the part that we play in it.

If you are skeptical of such optimism, I will say something that may sound controversial. I used to say this to my staff in the White House, young interns who would come in, any group of young people that I met with, and that is that by just about every measure, America is better, and the world is better, than it was 50 years ago, 30 years ago, or even 10 years ago.

I know that statement doesn’t jibe with the steady stream of bad news and cynicism that we’re fed through television and Twitter. But think about it: I was born, and I know I have grey hair but don’t consider myself that old, but I was born at a time when women and people of color were systematically, routinely excluded from enormous portions of American life. Today, women and minorities have risen up the ranks in business, and politics, and everywhere else, and even if we still have miles to travel, and innumerable laws and hearts and minds to change. The shift in what this country is and what it means, is astonishing. Remarkable, and its happened when you measure it against the scope of human history — in an instant.

Just since I graduated from college, crime rates, teen birth rates, dropout rates, the share of people living in poverty have dropped, in some cases dropped dramatically. The share of Americans with college education – is up. Despite a massive global recession in the final years of my presidency, the uninsured rate reached a new low, and the median household income reached a new high.

And that’s here in the United States. And worldwide, our progress is even more remarkable. Bill can rattle off these statistics better than I can, but over the past 100 years, we’ve come from a world where only a small fraction of women could vote to a world where almost every woman can. Since the 1950s, the global average life expectancy has grown by more than 20 years. Since 1990, we have cut extreme poverty and childhood mortality in half. Keep in mind I was in law school in 1990 — it seems like yesterday. Since 2000, we’ve evolved from a world without marriage equality to one where it’s a reality in more than two dozen countries.

All of this has happened in such a steady march that sometimes we have the tendency to take it for granted. But I often ask when I meet with young people: if you had to choose any moment in history in which to be born, and you didn’t know in advance whether you were going to be male or female, what country you were going to be from, what your status was… you’d choose right now. Because the world has never been healthier or wealthier. Or better educated. Or, in many ways, more tolerant. Or less violent than it is today. Fewer people are dying young, more people are living not only longer, but better. More girls are in school; more adults can read; more children get the vaccines that they need. Despite the enormous conflicts that break our hearts around the world, it’s demonstrable that fewer people being killed in wars or conflicts than ever before. This would be the time you’d want to be, showing up on this planet.

These trends are real. They do not make us complacent, but they should spur us to action because it shows, despite the naysayers and the cynicism, that in fact, change can happen. They’re not the result of mysterious forces of chance. They happened because countless people, like you, toiling for many years, chose to make this progress. Some, like Bill and Melinda, have enormous wealth and influence; others, like Justin Trudeau, who I know addressed you earlier, have formal political offices. But the majority of people who made these advances who made these advances were citizens. Doctors. Nurses. Entrepreneurs. Clergy. Moms. Community leaders. Activists. Union leaders… who mobilized, and organized, and voted, and innovated, and pushed for change. And by the way, they knew at every step of the way that they would not get everything they wanted as fast as they wanted. They knew that progress required struggle, and perseverance, and discipline, and faith. They knew that sometimes, for every two steps forward, you’ll take a step back. But they made things better. And this is something I always had to emphasize to my staff when I was president — better is good. You laugh but sometimes, people forget that. I will take better every time.

So that’s what’s needed today: the engagement of everyone who wants to see a better future for our children. And it can be frustrating. I’ll take an example here in the United States, over the past eight years. Thousands upon thousands of Americans threw themselves into the collective effort of reforming our health care system. Those of you who live in countries that already have universal health care are trying to figure out what’s the controversy here, I am too. But the folks who did the work, it wasn’t just policy wonks. It wasn’t just politicians. It was moms and dads. People who had the experience with a sick child, or crushing medical bills that threaten to bankrupt them. Maybe a parent who was lost to cancer that, had that person got a regular check up, might have been caught earlier. And those voices from every walk of like and every corner of the country, against all odds, made a difference. For the first time, more than 90% of Americans know the security of health insurance. Paying more for insurance, or being denied insurance because of a preexisting condition or because you are a woman – that’s not a thing anymore. We got rid of that. And people are alive today because of it, and that’s progress. Now, the legislation that we passed was full of things that still need to be fixed. It wasn’t perfect, but it was better.

So when I see those people trying to undo that hard-won progress, for the 50th or 60th time, with bills that would raise costs or reduce coverage, or roll back protections for older Americans or people with pre-existing conditions – the cancer survivor, the expecting mom, or the child with autism, or asthma, for whom coverage once again would be almost unattainable… it is aggravating.

And all of this being done without any demonstrable economic, or actuarial, or plain common sense rationale — it frustrates. And it’s certainly frustrating to have to mobilize every couple months to keep our leaders from inflicting real human suffering on our constituents. But… typically that’s how progress is won. And how progress is maintained, on every issue, we have to stand up for each other, recognize that progress is never inevitable, that it often can be fragile, it’s in need of constant renewal, and our individual progress and our collective progress depends on our willingness to roll up our sleeves and work, and not be afraid to work.

In conclusion, each of us can make a difference, and I know I’m preaching to the choir here because otherwise you wouldn’t be a goalkeeper. But many of you are young and maybe have only seen forward momentum and may not have seen backward momentum yet. Many of you may confront hurdles and roadblocks and disappointments in the future. And when that happens, that’s the test. The test is not how you feel when things are going good or when you are at a cool conference in New York with Bill and Melinda Gates, and Will I Am. The test is when you’re in the field and you’re on the ground and you are doing work and people are resisting or misunderstanding or purposely undermining efforts that you know can make a difference, and how you respond to that. And what I’m suggesting here today is that your response has to be to reject cynicism and reject pessimism and push forward with a certain infectious and relentless optimism. Not blind optimism. Not one that ignores the scale and the scope of our challenges – but that hard-earned optimism that’s rooted in the stories of very real progress that have occurred throughout human history. And the recognition that our successes – even though sometimes they’re small, or incomplete – accumulate, they build, and they create a trajectory that’s better and will mean some girl, somewhere getting an education that otherwise she wouldn’t have had. That’ll mean some farmer being able to cultivate a crop to feed his family and, if enough of them do it, feed a nation. That’s what you’re fighting for at every moment.

Because each new generation stands on the successes of the previous generation. It’s like a relay race that we’re running. Each generation reaches up, standing on that previous generation and bends that arc of history in the direction of more freedom, and more opportunity, and more justice. That’s why I spent so much when I was president convening young leaders on every continent that I visited. That’s why in my post-presidency my emphasis is going to be on training the next generation of leaders to take their own crack at changing the world through the Obama Foundation, which will be based in Chicago, but will have projects, programs, and digital networks all across the globe. And I’m hoping I get a chance to work with some of you, because I have great faith in you, just as I know Bill and Melinda have great faith in you. And I’m certain that if you keep pushing forward, then America and the world are going to be just fine. Thank you very much.