天长地久只是曾经爱过
[tiān zhăng dì jiŭ zhĭ shì céng jīng ài guò]
'Eternal love only means we have loved before', reflects a sense of loss or disillusionment about lasting love. This kind of online name often carries a hint of sorrow or cynicism regarding love or long-term relationships, indicating the feeling of love didn't last despite efforts.