It means that when we sit down and look at the lush grass and red flowers, our youth does not stay for us, but passes away like running water. Metaphor is not to linger for a moment of beauty, but to grasp youth and do meaningful things. This poem is signed by a user on Zhihu: gather like duckweed and scatter like a cloud, poor people live and die in Mo Wen. Yi Hong Yuan, Su Hua has a fleeting time and won't wait for you. This is not a "semi-impenetrable" and "mysterious" online poem, but a serious collection of poems. Poetry is a genre of poetry. Set, the meaning of set.