It's a tremendous honor to be here.

I know we're all hoping to be outside, but in this magnificent surroundings, I for one am enjoying the feeling that President Eisgruber is about to get out the sorting hat.

I've never been to Princeton before, and I arrived a day ago and had the opportunity to walk around and look at the place and look at the town, and to call Princeton picturesque is to pay a compliment to the pictures of the world.

Just walking down Nassau Street, the petrol stations look like Edward Hopper paintings.

I saw somebody taking their rubbish out, and the rubbish was a sort of weathered orange crate broken up and a 1930s rusted fan, and that was what they were putting out on the sidewalk.

Even your trash is more beautiful.

So I'm supposed to stand here today and tell you that, you know, not to worry, this wonderful environment that you've been in, that is indeed, you know, the envy of the world, an education you've had that is arguably the envy of the world, certainly the envy of Yale, and I'm supposed to tell you that the rest of your life you're not going to be regretting the fact that you've left here.

All I can really say is there's probably a reason 25,000 alumni came back for the reunions this weekend, but at least you've got that to look forward to.

I was lucky enough to go to a university, University College London, that had a similarly impactful relationship with my life.

That is to say, I carry it with me everywhere I go.

How important was it in my life?

Well, my wife, Emma, who's here today, who's also my producer, we met on the first day of college, and we made our first feature film at UCL.

So four kids, nine films, or nine kids, four films, I get confused, but lots of kids, lots of films later, we're still carrying it with us as an experience.

So we were very sad to leave, and when we sat there in graduation, we were very melancholy, as some of you will be, but we were ready to leave.

We were ready to get out there, and we felt very much as if we had accumulated this sort of whole wheel of brie, of knowledge.

Of course, what I realized is actually a Swiss cheese, and those gaps in there are the point.

They're the important part, because you're going to get out there, and you're going to fill those gaps that you don't even know you have, those gaps in your knowledge.

You're going to fill them with experience, some of it marvelous, some of it terrible, and you're going to learn that way.

But what you have achieved here will see you through that.

What you've achieved here, you haven't just learned a body of knowledge, you've learned how to learn.

You've learned the value of learning, and I can say, in all honesty, 20 years on, I'm a much better student now than I was when I was at college, and I think the same will be true for most of you, in truth.

You'll carry on learning, you'll carry on expanding, and most importantly, some of those gaps will be filled with the most precious thing of all, which is new thought, new ideas, things that are going to change the world.

As a believer in the concept of inception, as a believer in the idea that you can plant the seed of an idea that will grow into something more substantial over time, I do feel some responsibility to try and say something to you that you would carry forward and might help you in some way.

So I thought back to the world of my graduation, when Emma and I were sitting there 20-odd years ago, and I thought about what were the problems of the world, what were the terrible things we faced, racism, income inequality, warfare.

I could go on, but you know this list, and the reason you know it is it's exactly the same today.

And what that made me think is, well, what have we been doing for the last 20 years?

Because if I'm going to give you any advice, I have to sort of take a bit of a hard look about my generation, about what we have done.

And the truth is, I think we've failed to address a lot of the fundamentals, possibly for a good reason, and that reason is I think we went out into the world believing that if we could connect the world, if we could allow the free exchange of ideas across geographical boundaries, economic boundaries, if we could all talk, these problems would go away.

And unfortunately, I think by now we have to acknowledge that we were wrong, that that's not the case, that communication is not everything.

And so much of the resources, intellectual resources, financial resources of my generation have gone into communications infrastructure and achieved wonderful things, but perhaps not as wonderful as we claim them to be.

I mean, barely a week goes by that I don't read some comparison between a new way of sharing videos or something that's compared to the invention of the printing press.

And you only have to say that out loud to realize how silly that is.

The long and the short of it is, well, to give you an example, when I was flying out here, I had an experience that I've had with increasing frequency.

You get on an airplane on a day flight to take you across America, and the shades are down because they don't want the cabin to get too hot, save on the air conditioning, good idea, and nobody lifts the shade as you take off, nobody lifts the shade as you fly all the way across this amazing country, nobody looks out the window.

Everybody's there with their screen, with whatever it is they're doing.

I look out the window and people give me dirty looks because I'm interfering with the light on their screen.

And not to imitate one of your previous Class Day speakers, Stephen Colbert, you know, you could construe this as an insult to America.

I mean, we were flying over the Grand Canyon.

I would go further than that.

I would say it's an insult to reality.

Before I go any further, I have to acknowledge the irony that I am someone who made a film, half of which is set in the cabin of an airplane where people are dealing with realities within realities.

So I've certainly had my part to play in this, perhaps.

But when you're flying in an airplane across this incredible country, you're enjoying one of the great modern marvels.

You're getting a perspective on America, on our landscape, and where we are that no one's ever had before.

And it speaks to the theme that I want to introduce, which is a respect for reality.

I feel that over the last couple of decades, I feel that over time, we've started to view reality as the poor cousin to our dreams, in a sense.

We've started to think of reality as this kind of gray pebble at the center of wonderful abstract thought that transcends it.

And I want to make the case to you that our dreams, our virtual realities, these abstractions that we enjoy and we surround ourself with, they are subsets of reality.

Inception had something to say about this, and I apologize to those of you who haven't seen it, because I'm about to spoil the ending of it for you.

But at the end of the film, there's a spinning top that's spinning, and if it falls or doesn't fall is the key idea.

Is it a dream?

Is it reality?

And the way the end of that film worked, Leonardo DiCaprio's character, Cobb, he was off with his kids.

He was in his own subjective reality and didn't really care anymore.

And that makes a statement that perhaps all levels of reality are equally valid.

The camera moves over to the spinning top, and just before the spinning top appears to be wobbling, there's a cut to black, and I skip out of the back of the theater before people catch me.

And there's a very, very strong reaction from the audience, usually a bit of a groan, but the point is, objectively, it matters to the audience in absolute terms, even though what they're watching is a fiction, is its own virtual reality.

But the question of whether that's a dream or whether it's real is the one I've been asked the most about any of the films I've made.

It matters to people enormously, and that's the point about reality.

Reality matters.

It won't be transcended.

We had a dream of being outside for this occasion.

Reality intervened, and we're in here.

We live in the real world.

We deal in the real world.

And I think what I was saying earlier about communications, it's time for something of a new generation could do that my generation can't.

We are firmly embedded in the belief that we have changed the world in all kinds of incredible ways, and we have all kinds of ways of selling this to you, and we use fancy words like disruption, which is essentially a form of sort of economic nihilism, whereby you judge the value of a company by how much it can stop other companies making money rather than what they actually make themselves.

That's there for those of you going into finance, by the way, just trying to lay a little groundwork there.

And we use words, slippery words, like algorithm.

Okay.

Now, if you hear someone use the word algorithm, and they're not a mathematics professor or a computer scientist, they're probably trying to obscure what it is they actually do, what their company does.

At the very least, they're trying to evade any responsibility for what it is that their company actually does.

I would love for you to be suspicious of this.

I would love for you to look at fundamentals, to look at, okay, what are we really doing in the world?

What is the change that is being affected?

How can we actually move the ball forward, progress in this way?

Oscar Wilde once said, the old believe everything, the middle-aged suspect everything, the young know everything.

You do know everything.

I'm clearly in my suspicious phase, and I'd love to impart some of that to you, because I think there's an enormous amount of work to be done.

And in the great tradition of these speeches, I don't have to tell you how to do it.

And in the great tradition of these speeches, generally what happens is the speaker says something along the lines of, you need to chase your dreams.

But I'm not going to say that because I don't believe it.

I don't want you to chase your dreams.

I want you to chase your reality.

And I want you to understand that you chase your reality not at the expense of your dreams, but as the foundation of your dreams.

It's very, very important that you take the elevator position that you have achieved over these four years.

The advantage is that this fantastic education is conferred on you, and you do everything you can with it to improve the world, to improve reality.

In whatever field you're going off to work in, I think looking at fundamentals, looking at how people are really affected by what you do, I think you have limitless potential.

And there's been a certain amount of talk about Batman.

But nobody's pointed out the most important thing about Bruce Wayne, which is, yes, he attended Princeton, but he didn't graduate.

He didn't graduate, and so as of tomorrow, you are all already better than Batman.

You do me great honor by inviting me here to be a part of this very, very important time in your lives.

I am so excited for your future, and so very grateful for you inviting me here.

And I wish you all the best tomorrow, and indeed for the rest of your lives.

Thank you very much.