不以人之所不知告人,以所知告之。
不把别人所不懂的告诉别人,把别人知道的东西告诉别人。 
If you enter this world knowing you are loved and you leave this world knowing the same, then everything that happens in between can be dealt with.
一只眼睛的人可以用来看水平仪,有毒的石头可以用来治疗痈疽。