I understand that someone might be a valuable firsthand source to get interesting details and core pieces of a real story right. But how can someone secure the movie rights or book rights from them? Stuff happening to you doesn’t exactly mean you’ve created something and should have copyright, or does it?
Usually what makes it worth it is if the person in question has any works under copyright. It is usually fair game to make an unauthorized biography of a politician since very little of their public work is protected. In contrast, various artists, especially singer-songwriters, generally need to have their works be official since the copyright holders want control over how the artist is portrayed.