What I want to talk to you about today is the difference between gifts and choices. Cleverness is a gift， kindness is a choice. Gifts are easy -- they're given after all. Choices can be hard. You can seduce yourself with your gifts if you're not careful， and if you do， it'll probably be to the detriment of your choices.
幸福就在脚下，只要你愿意低头寻找。
理论物理学是唯一一个你可以通过犯错来谋生的科学。