Zhuang Zhou: It is Zhuangzi who once wrote a fable in On Everything, saying that he became a happy butterfly again in his dream, and he felt erratic when he woke up. This fable reveals the eternal proposition of "who am I".
Gao Shi: A famous frontier poet in the middle Tang Dynasty, he made friends everywhere when he was a teenager, and had poetic contacts with Li Bai and Du Fu, but he never became attached to Ke Di. He didn't enter Jinshi until he was 50 years old, but he got a small official in Xiancheng. He resigned because he was dissatisfied with welcoming the officials and flogging the people, and then went to Goshuhan. Since then, his career has flourished and he has been doing our time.
Phoenix voice: This sentence is based on "Little Phoenix is cleaner than the old wind". The original poem was written by Li Shangyin praising his nephew. Literally, it means "the song of Little Phoenix is more crisp and mellow than that of Old Phoenix", which means that young people are better than old people. This sentence is used in reverse here, which means "You can still make Yushan sing like a phoenix when you are old", which is a metaphor for an old horse or a late bloomer.
The meaning of this couplet is profound, and I can only explain the literal meaning:
Forget everything in the world, admire Zhuangzi's legacy, and still ask yourself "Who am I" in my dream; Learn poetry and be a man like Gao Shi, not afraid of being a late bloomer, but also be the voice of the phoenix when you are old.
I just saw your question, which may be a little late, but I hope it will help you.