Poetry, life, empty songs.

First of all, literally explain: a person's life is like a dream, and the process of birth, aging, illness and death is just a blink of an eye. The only thing that can truly exist forever is reason, which will never change no matter the change of time or space.

Second, extended to the explanation of life: human life is very short. Only by strengthening our faith in a short time and persisting in those goals worthy of the brilliance of life is the meaning of our life.

Thirdly, it is extended to philosophical explanation: human life is short and ethereal, and only nature and law are eternal. In that case, what's the point of living? It is to know nature, know laws and treat our environment and life objectively in a short life.