? What does it mean to float like a dream? What are the allusions?

The source of the allusion: Zhuangzi deliberately told Zhuang Zhou: "If his life floats, his death will rest. Idiom meaning: floating life: an empty and illusory life; If: like it. Imagine life as a short and illusory dream. Idiom phonetic notation: ㄨˊㄕㄥㄖㄨㄛˋㄇˋㄥˋˋˋㄥˋㄥㄥㄋㄋㄋӻӻӻӻӧӻ1 As object and complement; Life is like a short dream. Idiom structure: English translation of subject-predicate idioms: life is short as a dream