How to understand "moonlight is still the moonlight of teenagers, and Kyushu is still the frost of Li Bai"?

The color of the frost on the motherland is still the same as that of Li Bai at that time, which means that the country has never changed color, but the young head has turned white.

This sentence comes from Yu Guangzhong's monologue.

Yu Guangzhong published 2 1 kinds of poems; Prose collection 1 1 species; 5 kinds of comment sets; 13 translation; * * * More than 40 kinds. His representative works include White Jade Bitter Melon (a collection of poems), Memory as Long as a Railway (a collection of essays) and On the Watershed: A Collection of Comments by Yu Guangzhong (a collection of comments). His poems such as Nostalgia and Four Rhymes of Nostalgia, as well as his essays such as Listening to the Cold Rain and My Four Imaginary Enemies are widely included in Chinese textbooks in Chinese mainland, Hong Kong and Taiwan.

Personality assessment

Yu Guangzhong writes poetry with his right hand and prose with his left hand. His achievements are as high as ever. (Comment by Liang Shiqiu)

Yu Guangzhong mainly writes poems and is famous for his essays and comments. His poems often express the poet's sympathy, concern for the land, mention of environmental protection, and perspective analysis and capture of all modern things. The author starts from tradition to modernity, and then goes deep into tradition.