竹马老去青梅枯萎
[zhú mă lăo qù qīng méi kū wĕi]
A cultural reference from the saying 'youth companions since childhood (青梅竹马)' turning into old age ('old bamboo horse' 竹马) and decay ('withered plum flower' 青梅). It illustrates childhood friends growing apart over time, symbolizing inevitable change and nostalgia for early innocence lost.