人之有德慧術(shù)知者，恒存乎疢疾。
【解釋】人常常在憂患困苦中，才能磨練意志，增長(zhǎng)才干。
杰夫·貝索斯接受了萊克斯·弗里德曼的播客采訪
"The only thing that one really knows about human nature is that it changes."
Mathematics is a creative endeavor, just like art or music.