你的笑容我的旧梦
[nĭ de xiào róng wŏ de jiù mèng]
'Nǐ de xiào róng wǒ de jiù mèng' which could be explained as 'Your Smile, My Old Dream', suggesting an old reminiscence associated with the smile of someone significant. This internet nickname expresses some sort of melancholic nostalgia.