"Didn't I only sleep for three days? Why has the weather changed???"
The change began that summer, which was also the summer when Teacher Yan Yang's inexplicable "son" suddenly appeared.
"Xiaoyang is here. Let me introduce you. This is my son, Zhuchi."
"Come on, Zhuzhu, this is the student I am most satisfied with, Yan Yang, whom I have often told you."
Idea: Where do so many coincidences come from in the world?