你不能以貌取人，但你可以通过第一章来判断一本书。
You can't judge a book by its cover, but you can by its first chapter.
最好的书会提出问题，而不仅仅是给出答案。
我不是英雄，我是反派。
To change one’s life: Start immediately. Do it flamboyantly. No exceptions.
"Randomized experiments are the gold standard for causal inference, but they are not always feasible."
互联网是教育的强大工具，但它不能替代教师。
The aim of art is to move the heart.