可能不舍的不是你而是昨天说着不想不念心里却还留恋
[kĕ néng bù shè de bù shì nĭ ér shì zuó tiān shuō zhe bù xiăng bù niàn xīn lĭ què hái liú liàn]
Translated, this becomes: 'Possibly what I can't give up is not you, but the yesterday, saying I didn't think about missing anything, while there was still lingering nostalgia'. This indicates a bittersweet feeling where a breakup might seem easy but letting go the memories is hard