And even then, as she’s learned via Cillian, whom she’s known for more than twenty-five years, people can still surprise her, in both good and bad ways.
-- Vincent (Part One: Vincent & Cillian: 2)

Importance: This quote shows how much Cillian’s book has hurt Vincent. Not only has it caused her to no longer trust Cillian, but it also hinders her from believing other people. She is cautious, angry, and feels that others will fail her if her closest companion did. However, there is also a glimmer of hope in the quote itself, as Vincent acknowledges ‌that people can surprise her in good ways too. This thought prevents her from becoming completely reclusive. She can still believe in others, even if she is more hesitant to trust than before.

She could be mad at him and carry on. But she told him anger wasn’t a state she could choose to stay in for very...
-- Vincent (Part One: Vincent & Cillian: 3)