The secret of life is to appreciate the pleasure of being terribly, terribly deceived.
The first condition of understanding a foreign country is to smell it.
——在遗嘱上签名，稍休后说几句话勉励各同志，1925年3月11日
The essence of mathematics is not to make simple things complicated, but to make complicated things simple.
The hardest thing is to live richly in the present without letting it be tainted by the past or future.