女人心若海底针男人心若陆地石
[nǚ rén xīn ruò hăi dĭ zhēn nán rén xīn ruò lù dì shí]
'A woman's heart is like a needle at the bottom of the sea; a man's heart is like a stone on land'. This metaphor expresses the depth and subtlety of a woman’s emotions compared to the more rigid and straightforward nature of a man's heart.