她有什么好值得你念念不忘
[tā yŏu shén me hăo zhí dé nĭ niàn niàn bù wàng]
'What is so good about her for you to keep remembering?' It shows dissatisfaction or envy from someone who doesn't understand why another person is so hard to forget, reflecting on a complex relationship dynamics filled with admiration and maybe bitterness.