Dr. William talks too much.
But instead of stopping him, Aaron lets him finish his story.
And he's suddenly enlightened by it.
Dr. William is right.
Katrina is, indeed, like that bird in the cage. She longs for freedom and equality. But he persisted in keeping her by his side forcefully and on his own terms. Even his kindness for her is imperious and overbearing.
Dr. William said he forced the bird's mouth open and fed it food.
At the thought, he realized that he also did the same to her.
When Katrina was in a temper and refused to eat, he's also force-fed her with his mouth.
Although Katrina has no wings, he undoubtedly hurt her though his actions and caused the fear and resistance she felt towards him.
Her subsequent obedience to him is only a way of protecting herself.
After thinking over it carefully, he finds that even if he repeatedly says that he will be kind to her, in the end, he hurts her a lot.
