我本无心何来刻骨铭心
[wŏ bĕn wú xīn hé lái kè gú míng xīn]
Literally translated to ‘If I have no intention, how could it leave a mark that cuts bones into pieces’- which refers to saying one can only be profoundly moved by someone or something when one cares enough about them, and having no intentions from the beginning leads nothing left but regret.