As for my question about the difference between
I like a movie, Pulp Fiction.
I like the movie, Pulp Fiction.
A commenter answered: I would say the only difference in usage is that you would use the first sentence when talking to someone if you didn't know whether they'd heard of Pulp Fiction. You would use the second sentence if you know they've heard of the movie.
In short, the commenter says the usage of 'the' is associated with the listeners' knowledge of the topic. However, when I think of the movie title, The English Patient, it's not associated with the listeners' knowledge of the topic; the audience has never heard of the specific patient.
I can't say 'I bought the book' unless the person I'm talking to knows of the book already, right? But the filmmakers use The English Patient even though the audience doesn't know of the patient yet. Can we use 'the' even though the people we are talking to don't know about the topic? What are the rules?