Willows are an image that often appears in Chinese poetry. This sentence uses the technique of borrowing scenery to express emotion, which means that I want to explain that my thoughts and melancholy for more than 40 years have lasted as long as the fluttering willows.
The word "Liu" for "willow" is homophonic to the word "Liu". Mentioning "Liu" will naturally create an artistic conception of retaining guests and relatives in people's minds.
Breaking willows represents farewell, and willows are used to express the deep feeling of farewell. The image of willows is suggestive and inspiring.
Since the Han Dynasty, broken willows have often been given as gifts to express the feeling of attachment and farewell, thus triggering the longing for relatives far away and the homesickness of travelers.