I have already carried out my duty. I have proved the Poincaré conjecture and I have nothing more to do in mathematics.
"Words have the power to heal and to destroy."
 “每逢你想要批评任何人的时候”,他对我说,“你就记住,这个世界上所有的人,并不是个个都有过你拥有的那些优越条件。”
"The only limit to our realization of tomorrow will be our doubts of today."