柠檬酸口不酸心蜂蜜甜口不甜心
[níng méng suān kŏu bù suān xīn fēng mì tián kŏu bù tián xīn]
Means 'lemons taste sour but do not make your heart sour; honey tastes sweet but does not touch your heart.' It compares the bitter and sweet aspects of life or emotions, suggesting that external appearances may differ from inner experiences.