休说生生花里住惜花人去花无主
[xiū shuō shēng shēng huā lĭ zhù xī huā rén qù huā wú zhŭ]
Don't speak of living among the flowers because once the person who cherished these flowers is gone, there's no one left to appreciate them. This phrase conveys nostalgia for something precious that no longer exists and mourning its absence.