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.

The only way to get better is to keep doing it.

Sometimes the hardest part isn't letting go but learning to start over.

Believe in yourself and all that you are.

一个物理符号系统具备一般智能行为的必要和充分条件。