《淮南子·诠言训》
如果去追求尚未得到的那一份，就有可能连原有的那一份也会失去；保持着已有的一份，那么所希望的东西自然会来到。
求其所无，则所有者亡矣；修其所有，则所欲者至。
If you pursue what you do not have, you will eventually lose what you have. Hold on to what you have and what you desire will come to you.