Analysis:
From Juck Zhang's Shadow of Dreams (III), On the Spring and Autumn Period.
Translate in vernacular, namely:
Spring is the true face of nature, and autumn is just an extra sight and mood.
The author identified the feeling of Spring and Autumn, and linked "Spring and Autumn" with treating people with things. So the following just said:
"Self-discipline should bring autumn, and life should bring spring."
"Spring rain is like a letter, and autumn rain is like an elegy."
In the final analysis, it is because spring is lush and full of vitality; On the contrary, in autumn, plants wither and death is everywhere.