Trivia: Kevin Nash's hands were too large to fit into his coat pockets, and they became very cold as a result. His request to have the pockets cut larger was denied because the coat was an expensive rental. When Keanu Reeves learned of this, he demanded they cut his pockets larger.
Trivia: Chad Stahelski, the director of the John Wick films, had worked as Keanu Reeves' stunt double for 15 years prior to his directorial debut on this film.
Trivia: Two legendary Keanu characters with the same first name drive the same car, just one year apart. John Wick rolls in a 1969 Ford Mustang Mach 1. Johnny Utah, in Point Break, drives the 1970 version.
Trivia: Chad Stahelski has revealed that he and Reeves have a host of ideas for future instalments in the series, and are happy to keep making future films as long as the audience demand is there. "I enjoy making these movies because there's no limit, " said Stahelski. "We create our own mythology, and we have a studio that both stays out of our way and supports us on the wacky decisions. If people go see the movie, and it makes money, and they came back to us, Keanu and I have ideas for days." https://www.flickeringmyth.com/2018/12/chad-stahelski-and-keanu-reeves-have-plenty-of-ideas-for-more-john-wick-movies/.
Answer: In Hollywood, anything's possible. However, it would mean removing much of the mystique surrounding the character. Part of the reason Wick works so well is the mysterious back story.