There is an upsetting amount of Neville Longbottom's backstory that is left out of the movies. So much so, that even Matthew Lewis, the actor who plays the part of Neville, feels that his character kind of got gypped. Neville, although he seems to be a secondary character, is actually part of the glue that ties many of the story's characters and plots together. So understandably, it can be easy to dismiss Neville as a background character if you have only seen the movies.