你不是我不用懂得我的难过
[nĭ bù shì wŏ bù yòng dŏng dé wŏ de nán guò]
This can be translated as 'Since you're not my partner, you don't need to understand my sadness'. It conveys a sense that the other person doesn't need to understand one's sorrow because they are not emotionally connected enough.