We bet most of the teenagers you know don't have cancer, right? We can thank our lucky stars for that, but for Hazel, Augustus, and Isaac in The Fault in Our Stars, that means a whole lot of isolation. Sure, Hazel hangs out with her friend Kaitlyn, and Isaac starts off the book with a lovey dovey girlfriend, but when the going gets tough, their illnesses separate them from most other people. Add that to their physical limitations, and they find themselves in a world that is oftentimes very, very lonely.
Hazel and Augustus fall deeply in love because they both understand what it's like to be different from other kids, and how awkward and lonely that can be.
A part of Hazel's isolation is self-imposed because she is so intent on not hurting other people.