The birds of pandemonium what is the main role of the paragraph

Chastened, I searched all over and found another source that had some in stock. The clerk asked me if I wanted to have the worms coated in vitamins. It had never occurred to me to do this, but I realized it was a good idea. After that, I used worms as a delivery system for powdered vitamins and any necessary medications for many other birds. Score another lesson for Sweetie.
This was a procedural advance, but the bigger lesson I was about to learn was this: listen hard enough and you'll realize that a bird can communicate with humans, and in more than one way.

The main role of the paragraph is to illustrate how the narrator learned a lesson from their bird, Sweetie, about listening to birds and understanding their communication.