Why should the author use imagination in two poems by Guo Moruo, the first volume of Chinese in the first day of junior high school?

At the beginning of last century, China was still in the darkness of semi-colonial and semi-feudal society. The May 4th Movement called on people to pursue freedom, happiness and a better life. However, after the movement, China was still under the rule of the Northern Warlords, and a free, beautiful and happy life still did not come, which made many people desperate and helpless, but the poet did not give up hope. He rewrote the myth, imagined the Cowherd and the Weaver Girl living a happy life in the sky, and expressed his resistance to feudal oppression and his yearning and pursuit for the ideal life of freedom and happiness.