满口永远的孩纸慢慢懂事
[măn kŏu yŏng yuăn de hái zhĭ màn màn dŏng shì]
It translates to something like 'Forever Child Learning Maturity Gradually'. The netizen seems playful while slowly coming to grips with reality - still maintaining a sense of being eternally youthful, yet recognizing the importance of wisdom that matures over time.