致我们早已逝去的童年
[zhì wŏ men zăo yĭ shì qù de tóng nián]
This internet username 'To Our Long-lost Childhood' conveys nostalgia for the past. The phrase reflects a sentimental reminiscence of childhood, which has passed by and no longer exists in its original innocence or carefree days. It's commonly used to express the feeling that childhood will never return.