Trivia: Choi Min-sik had to eat four live octopuses for the infamous scene in which his character Oh Dae-su wants to "eat something alive." Min-sik is a Buddhist, and would pray before each take and profusely apologize to the octopuses before eating them. The director later personally thanked the octopuses during an acceptance speech for an award he got for the film.
Trivia: The second entry in the "Vengeance Trilogy" by director Park Chan-wook. The three films are not directly related, but are connected by similar visual styles and themes of revenge and retribution. The first film was "Sympathy for Mr. Vengeance," while the final film was "Lady Vengeance." All three films have been optioned for American remakes, although as of 2019, only "Oldboy" has been successfully remade.
Trivia: One of the 'fighters' in the corridor fight never actually does any fighting - he's there to make up the numbers. He moves forward as if about to attack, but then moves to the back when a piece of action happens against Olboy, such as 'one on one' or stick attack etc.
Trivia: The one-shot fight sequence was a nightmare to film. The director wanted to actually film the scene in one take (as opposed to multiple takes being cleverly edited together), using as little CG as possible. It ended up taking three days to film to get it just right, and was exhausting for star Choi Min-sik. The only CGI used in the scene is the knife sticking out of Oh Dae-su's back, and a few small tweaks to mask missed punches.
Trivia: The film is based loosely on a Japanese manga of the same name. The filmmakers used the manga (which was unfinished at the time of filming) more as a "jumping off point," and used the basic set-up (a man is imprisoned for many years and then released), while taking creative liberties for the bulk of the story.
Trivia: Actor Cho Min-sik lost over 20lbs and worked out for many weeks to get into shape for the film for the scenes set in the present. The sequences set in the past were filmed later towards the end of production. Min-sik simply stopped working out and regained the weight he'd lost so he'd look more like a burnt-out slob in order to show his character's physical changes.
Trivia: In addition to the American remake in 2013, "Oldboy" was also unofficially remade in Bollywood as "Zinda" in 2006. The Bollywood remake was completely unauthorized, causing Show East (the distributor of "Oldboy") to threaten legal action. However, the studio that produced "Zinda" went out of business, and thus no legal action was taken.
Answer: Perhaps because in the movie/book "The Count of Monte Cristo" that's what happened to him. In the book/movie the hero Edmund Dantes is renamed "the Count" in order to disguise that fact that he is Dantes after having broken out of jail. This way he is free to seek revenge on the ones that put him in jail under false charges.
CCARNI ★