薄凉少年不懂情薄情少女不懂爱
[bó liáng shăo nián bù dŏng qíng bó qíng shăo nǚ bù dŏng ài]
'The Cool-Hearted Boy Doesn't Understand Love; The Heartless Girl Doesn't Understand Affection.' This implies a lack of understanding or depth in emotional matters. It reflects immaturity or indifference in romantic relationships.