拥有你却忘了说爱你爱上你却忘了留住你
[yōng yŏu nĭ què wàng le shuō ài nĭ ài shàng nĭ què wàng le liú zhù nĭ]
It means even though I have you in my life, I forgot to tell you my love and eventually let you slip away from me; it’s an expression of remorse and missed chances in expressing one's true feelings.