The meaning of this sentence is: Life is short, like a dream, full of illusion and beauty. When the prosperity passes, everything disappears like passing clouds and smoke. In this process, we will find that returning to the truest and simplest nature is the most beautiful.

This expresses an understanding of life, believing that life is like a dream, with an illusory and beautiful side, but also short and perishable characteristics. After prosperity passes, material enjoyment and prosperous scenes will disappear. Only the most real and authentic things can last and be the most beautiful. This is a life attitude that advocates simplicity and returning to nature.

The origin of this sentence is unknown, but it is similar to the poem "The king hides his face and cannot be saved, but looks back at the blood and tears flowing harmoniously" in the "Song of Everlasting Sorrow" by the poet Bai Juyi of the Tang Dynasty. It is also similar to the philosophical thought of "The Great Way to Simplicity" in the Tao Te Ching, that is, it is believed that the true Great Way is simple and natural.