LitCharts assigns a color and icon to each theme in Paper Towns, which you can use to track the themes throughout the work.
Perception vs. Reality
Authenticity and Artificiality
Human Connection
Leaving Home and Growing Up
Friendship
Summary
Analysis
As they get close to Agloe, Lacey and Quentin begin listing everything they know about Margo, from the make of her car to the color of her hair. Ben points out that they already know this information, but Quentin does not care. He wants to remember Margo now, while he is still hopeful that he will see her again.
Quentin knows his ideas about Margo may soon dissolve, and talking through his memories and perceptions of her is a way of reconciling himself to that possibility rather than denying it. He is preparing himself to accept whatever he finds in Agloe, regardless of whether it is what he hopes to find.