How does Clemantine use the metaphor of the bird in Chapter 17?

In Chapter 17, Clemantine discusses how two people might view an instance where a bird hits a window differently. If the people do not discuss their history and how it affects their perceptions, it is difficult to know why an incident like the bird is viewed differently. Trauma affects how a person sees themselves and the world around them and pieces of self are stolen by trauma. The violence could keep a person from really living their life.