A mathematician's work is mostly a solitary pursuit, but it builds on the work of many others.
善于学习的人,能够透彻地知道事情的道理;善于实践的人,能够把事情疑难之处弄清楚。
The best moments in our lives are not the passive, receptive, relaxing times… The best moments usually occur if a person’s body or mind is stretched to its limits in a voluntary effort to accomplish something difficult and worthwhile.