要走的人留不住
[yào zŏu de rén liú bù zhù]
This name conveys the feeling of helplessness in face of farewell, suggesting that a person who wants to leave can't be detained no matter how much others want to retain him. It's usually used in context where someone is leaving a job or a personal relationship. There might even be emotional attachment involved but one party chooses to go, and the other side can only accept the fact.