What theme does drinking Yangtze River water express?

"I miss you every day and drink the water of the Yangtze River without seeing you" is a love poem by Bai Juyi, a female poet in the Tang Dynasty, which expresses her longing for her lover who has traveled far away. According to relevant information, this poem expresses the author's longing for his lover by describing the beautiful scenery of the Yangtze River and recalling the situation of drinking Yangtze River water with his lover. The recurring words "riri" and "missing" in the poem strengthen the author's longing and longing to be with his lover. At the same time, the poem also reveals a romantic feeling, which closely links the beauty of nature, the emotions between lovers and the meaning of life, showing the author's high poetic realm and emotional depth.