John Green has revealed that a girl named Esther Earl was his inspiration in writing The Fault in Our Stars. Esther was diagnosed with cancer when she was still 12 years old. She died at 16, just a few days after her birthday in 2010. Esther was a certified fan girl and she met John Green at the Harry Potter convention named LeakyCon.
Watch the video below and see how John Green talks about his friendship with Esther.