Which poem of Du Fu can express positive optimism?

The wind is fast and high, the ape cries sadly, and the birds are circling in the white sand. The endless trees are rustling leaves, and the Yangtze River is rolling unpredictably. Li in the sad autumn scenery, a wanderer all the year round, lives alone on the high platform in today's illness. After all the hardships and hatred, the white hair is full, and the wine glasses are damaged. This is Du Fu's swan song "Ascending the Mountain". No one denies the artistic achievements of this poem, and some even praise it as "the first of the seven laws of ancient and modern times"; However, there are different understandings about what kind of spirit this poem shows. In 2004, I made a graduation thesis entitled "Poems of Jiangshan and Soul —— On the Poems of the Yangtze River and Li Bai and Du Fu". At that time, I thought this poem mainly reflected Du Fu's "life consciousness". The following is my analysis of this poem in my thesis: Du Fu mainly works for Confucianism, which knows that it is impossible to work for him, and his attitude towards life is vigorous, which makes him more aware of the endless rivers. His "Up the Mountain" is not only a sad autumn, but also a high sense of life: ... This poem was written in the second year of Dali (767) and lived in the southwest for a long time in his later years. At this time, it was only three years since Du Fu's death. According to the research of modern scholars, Du Fu was already suffering from severe diabetes and became weak. Many diseases followed, and he was no longer feeling well all over. In the autumn of this year, Du Fu boarded the bank of the Yangtze River, and what he saw was an unusually open scene: strong winds in the sky, apes sobbing in the sky, and birds homing in the clear lake and white beach. Writing about scenery has also become the main scenery: the sorrow of apes whistling and birds singing vaguely reveals unbearable sadness. The poet looked up at the endless rustling leaves, looked down at the rushing river and expressed his feelings deeply. Endless and inexhaustible, it makes the rustling roll more vivid, reminds people of the rustling of fallen trees, reminds people of the surging Yangtze River, and at the same time conveys the feeling that the glory is fleeting and the ambition is hard to pay. However, is the poet so depressed? Don't! When you look at the first couplet, the poet's voice, color, shape and posture are full of autumn. Isn't it suggesting that although we poets are old and lonely, our feelings are still rich and keen? "Leaves fall like the spray of a waterfall, but I watch the long river roll forward all the time." In the overlapping words of "rustling" and "rolling", it seems to exude the power of hidden undercurrent and surging momentum: isn't this a symbol of endless vitality? Isn't it a portrayal of "Tian Tianjian, a gentleman strives for self-improvement"? The poet stood on the edge of the Yangtze River, and for an instant, time seemed to stand still. Poets are integrated with everything in the world and always live in harmony with history. However, this is impossible after all. Comparing the brevity of life with the eternity of the universe, the poet deeply feels the inadequacy of life. This awakening of life consciousness inspired him to make up for the lack of its length with the intensity of life. It is such a place thousands of miles away.