Step-by-step explanation:
Looking to pg.199 of the book 'Paper Towns', it states:
"Chuck Parson was a person. Margo Roth Spiegelman was a person, too. And I had never quite thought of her that way, not really; it was a failure of all my previous imaginings."
Quentin realizes that Chuck Parson and Margo Roth Spiegelman are people too, ones that can feel pain and have dreams.