It's a story that often delves into the experiences of Marines. It might explore their training, the camaraderie among them, and the challenges they face in military life.
I'm not sure specifically which 'jarhead novel' you're referring to. There could be multiple novels with that name, so it's difficult to determine the author without more context.
To some extent. The movie takes elements from real-life situations but also incorporates fictional elements for dramatic effect. So, it's a mix of truth and creative interpretation.