此心非彼心此情非彼情
[cĭ xīn fēi bĭ xīn cĭ qíng fēi bĭ qíng]
It translates to 'this heart is not the same as that heart, this emotion is not the same as that emotion’. Used often in love scenarios to indicate misunderstanding, changes over time in love or feelings, or conflicting emotions.