可能不舍得不是你而是昨天说着不想不念心里却还留恋
[kĕ néng bù shè dé bù shì nĭ ér shì zuó tiān shuō zhe bù xiăng bù niàn xīn lĭ què hái liú liàn]
'It might be not you I can't bear to part with, but the yesterday that left me lingering despite saying I wouldn't care nor miss'. The nickname captures a poignant reflection about nostalgia or unrequited sentimentality. It conveys that what one really cannot forget or has been holding onto is a past feeling or time rather than the actual person involved.