John Green & Writing 'looking for alaska'
At the time John Green was writing 'Looking for Alaska', not a lot was going through his life. He was just writing it because similar events had happened to him when he was younger. The setting of the book was in Culver Creek Boarding school, but in real life he actually attended Indian Springs School, which is also a boarding school. The description of Culver Creek is very similar to his school, Indian Springs, according to him. He has also said, in a Q&A on his website, that the character of Alaska Young is also similar to a classmate who also passed away while he was attending Indian Springs. He goes on to explain that his relationship between him and the classmate was not anything like Pudge and Alaska's relationship or level of closeness, it was a very shocking and traumatic incident that affected everyone. Ever since, he has never forgotten her because, although, he wasn't close to the classmate he "admired" and "liked" the person very much. At the end of his Q&A he says, "... the story that resulted is truly imagined and I hope that it will be read that way." To finalize, this might've been a factor to why the book was brought to an end the way it was.
John green character comparison
John Green has definitely said before that he sees himself as Miles "Pudge" Halter. Especially, if almost half of the book is based on his life when he was younger. He has also said in another Q&A in his website that he could relate to Alaska's character. He says that he was "pretty reckless" when he was in high school and that he too "struggled against self-destructive impulses," very similar to Alaska's character. Although he also says that both of them were also different in many ways, such as: he "wasn't living with grief the way she was" and he also had "a better support system," unlike Alaska who dealt with grief and didn't really have anyone to rely on.