Didn’t Do Math At Hogwarts

(A customer is renting ‘Harry Potter: Harry Potter and the Deathly Hallows: Part 2.’)

Customer: “Have you watched this?”

Me: “Yes, but I found the books to be much better.”

Customer: “How can you like the work of some lazy author?”

Me: “Huh?”

Customer: “There are eight movies, but only seven books. The author got lazy and wrapped everything up in seven books instead of writing eight!”