怀旧的尘埃
[huái jiù de chén āi]
It translates to 'Dust of Nostalgia.' This username implies the user tends to reflect on the past nostalgically. 'Dust' symbolizes the long-gone and hard-to-seize nature of old memories. It indicates the owner of this username has a longing for things of the past which are now intangible, just like dust scattered in the wind.