丢了姑娘就别想找回来
[diū le gū niáng jiù bié xiăng zhăo huí lái]
When a person named in a loving or close context is described using the word '姑娘'(meaning 'girl') as lost, it is hard to retrieve. Often this is a metaphor for losing a chance, missing someone, or letting an opportunity slip by and acknowledging it can't return.