The more afraid Wang Luyu was, he forgot how to approve the form paper. He actually wrote eight big characters on the form paper: "Although you mowed the grass, I was scared by the snake." This means that you are doing this to mow the grass on the ground, but I am like a snake hiding in the grass, but I am greatly shocked!
Later, according to Wang Lu's eight words "Although you mow the grass, I am surprised", it was extended to the idiom "startle the snake".