柠檬已变甜柚子已无味
[níng méng yĭ biàn tián yòu zi yĭ wú wèi]
In Chinese culture, lemon (acidic fruit) and grapefruit (similarly acidic) can symbolize sour or unmet emotions which later matured through time, indicated by the lemons sweetening up - turning bittersweet or more bearable whereas grapefruits lose flavor – growing indifferent about those feelings.