幼稚永远是曾经旳
[yòu zhì yŏng yuăn shì céng jīng dì]
This username implies that being naive and immature is something from the past, a part of one's history. It suggests that the user has grown up and matured over time, leaving naivety behind as part of their memory. However, it also indirectly admits that immaturity was a significant aspect of their earlier self.