伤口不深不知疼感情不淡不知冷
[shāng kŏu bù shēn bù zhī téng găn qíng bù dàn bù zhī lĕng]
'Not Truly Hurt Until It Hurts, Unfelt Love Until Experiences Coldness' expresses understanding pain only when deeply wounded and realizing true feelings when having experienced cold-hearted situations, suggesting lessons learned from past emotional experiences.