念念不忘也只是回忆恋恋不舍也只是曾经
[niàn niàn bù wàng yĕ zhĭ shì huí yì liàn liàn bù shè yĕ zhĭ shì céng jīng]
This username expresses deep sentimentality and melancholy. The phrase means 'even if it’s unforgettable, it's just a memory; even if I’m reluctant to part with it, it’s still only from the past.' It reflects nostalgia for what has been lost but is not forgotten.