When going to pick up Augustus to leave for Amsterdam, Hazel overhears part of a fight between Augustus and his mom. She hears him yell at his mom, "BECAUSE IT IS MY LIFE, MOM. IT BELONGS TO ME." This foreshadowed to the reader that something was going wrong in Augustus's life, which there was. He had been fighting with his mother about going to Amsterdam because he had recently discovered that he had cancer cells all throughout his body.