Can someone explain to me what happen here.

Craaaazyyyy 😜🤪... that's where I'm feeling at home, hahahahawuahhh lets start with eg. the Wolf class. It extends StoryItem. Cause it extends StoryItem you can access the lists defined in the StoryItem abstract class using a Wolf object. And as luck would have it CG has already created such a static object for us... the wolf. With the above info you now know that wolf.ate is referencing a list (the list is a field, an instance variable... so each object has its own). When wolf.ate is referencing the list and the list takes StoryItems then you could put objects of every object derived of StoryItem into that list using the well know add method. Now we have wolf.ate.add() and we now just need to push the grandma object into the wolfs mouth: wold.ate.add(grandmother); yeah, yeah... that's crazy... I'm dancing like little red through the woods 🤪😜