白天不懂黑夜的黑黑夜不懂白天的白
[bái tiān bù dŏng hēi yè de hēi hēi yè bù dŏng bái tiān de bái]
'Day does not understand night’s blackness; Night does not understand day’s whiteness.' This metaphorical statement suggests mutual misunderstanding or contrast between different perspectives or lifestyles.