我姓王也忘不了你我姓刘也留不住你
[wŏ xìng wáng yĕ wàng bù le nĭ wŏ xìng liú yĕ liú bù zhù nĭ]
These sentences combined mean 'I can't forget you even if my surname is Wang (which phonetically implies forget) or I cannot retain you no matter my surname is Liu (similarly, a play on the word retain). It reflects the intense emotions and helplessness of a person who remains devoted despite their efforts not being reciprocated.