The beginning of the story is when she mentioned that the fallen leaves in Beijing are not as good as the parasol trees in her hometown.
She said, "If you please tell me that the sycamore tree is beautiful, I will plant it all over Jinling."
He said, "Humanity needs beautiful legends, and children are still at an age where they believe in beauty."
Just as the story begins, so does the story's end.
He has reached the age where he sneers at true love against all odds, while she is still sacrificing her innocent heart for love