1. In this sentence, the poet compares the sorrow of returning home to flowing water going east. The word "man" turns the abstract emotion into a concrete scene before the eyes, allowing the reader to clearly feel the poet's richness. The meaning of homesickness.
2. Disagree. One or two sentences in the poem express the poet's longing for home after living in a foreign country, and three or four sentences describe the poet going to the riverside to enjoy the flowers and scenery. The purpose is precisely to relieve the homesickness and sadness caused by the military expedition. To say that watching the flying flowers makes you forget to think about home is a contradiction in truth, and it is exactly a strengthening of the homesickness that the first or two sentences are intended to express.