This is called Tri-Quote Book, which comes from the first work in the Tri-Quote Book Competition of Wuhan University. At first glance, it is a classic.
List many impossible things one by one, and the last thing "you are thinking of me" is possible. It can be understood in reverse. I'm shelling a crab, I'm writing a notebook, maple leaves and snowflakes fall on my head, and I'm thinking about you, which is reasonable. The list of intentions is that only when the world is upside down can you miss me. It means: only when the world is upside down will you fall in love with me and express your helplessness and feelings for love.
Hope to adopt