Before Dawn and After Rain

In this world, there are so many Ding Xiaoyu and so many Wang Xiaoming. It is so lucky that they sit at the front and back tables, and it is so lucky that Ding Xiaoyu is always secretly happy with Wang Xiaoming. What does it matter whether this Ding Xiaoyu is the same Ding Xiaoyu or whether this Wang Xiaoming is the same Wang Xiaoming?