"Life is short, make every moment count."

The true test of a mathematical idea is its ability to inspire further thought.

The world is a very complicated place, and it's not getting any simpler.

And I hope you will come back here to Harvard 30 years from now and reflect on what you have done with your talent and your energy. I hope you will judge yourselves not on your professional accomplishments alone, but also on how well you have addressed the world's deepest inequities…on how well you treated people a world away who have nothing in common with you but their humanity.