The way that the shift that begins in line 21 affects the meaning of the poem is that; we must let each one go his own way.
The poem starts with a woman calling for her cat that had departed from the house.
Now, Cats are usually free and independent animals that do not always respond to their owners calls as it appears that they do not like to be controlled. However, the cat's owner wants to control it, but on line 21 she gives up and stops calling the cat.
Finally, although the beginning of the poem shows how we tend to control the people we care about, but however line 21 shows that we should let people go the way they want.
Read more about poem line shift at; https://brainly.com/question/14927409
