2004年9月13日，81岁的杨振宁在清华大学开始为本科生讲授普通物理。他说

Love isn't about when you first meet. It's about the many， many years you spend together， when you're trying to keep that flame burning.

Happiness is not out there for us to find. The reason that it’s not out there is that it’s inside us.

做出伟大工作的唯一方法是热爱你所做的事情。