People are afraid to pursue their most important dreams, because they feel that they don't deserve them, or that they'll be unable to achieve them. We, their hearts, become fearful just thinking of loved ones who go away forever, or of moments that could have been good but weren't, or of treasures that might have been found but were forever hidden in the sands.

科学无国界，因为知识属于人类，是照亮世界的火炬。

If a writer doesn't generate hostility, he is dead.

The beauty of instrumental variables is that they allow us to see the world in a new light.