One of the funniest running gags in How I Met Your Mother is how Barney Stinson (Neil Patrick Harris) there are always roots for the bad guys in movies and shows. He thinks King Joffrey was a "fair and wise ruler" on Game of Thrones and cheers for Hans Gruber during Die Hard. It's a joke that makes sense for Barney, an amoral agent of chaos who should probably be in jail, but it's one you could spend all day unraveling the logic of. How far exactly does Barney's villain worship go? Does she also root for Frank Booth in Blue Velvet or Hans Landa in Inglourious Basterds? I sure hope not!

Thankfully, "HIMYM" limits its examples of Barney's villain worship to less serious films. Most notable is "The Karate Kid," where Barney roots for blond bully Johnny (William Zabka) rather than angry outsider Daniel (Ralph Macchio). In season 4, Barney explains his reading of the film, saying: “It's the story of a promising young karate enthusiast whose dreams and moccasins take him to the All Valleys Karate Championship. Of course, unfortunately, he loses in the final round to that underage kid, but he learns an important lesson about accepting defeat gracefully."

It seems like a one-off joke, but four seasons later the real William Zabka shows up at Barney's bachelor party, thanking him for showing that someone else "finally" understands what The Karate Kid is all about. It's one of the best moments of Barney's life, thrown into one of the best episodes of Season 8. Zabka would go on to make regular appearances in season 9 of the show, even becoming Barney's godfather for a bit there.

Many fans credit this story with predicting "Cobra Kai," a popular TV series that debuted in 2018 and followed the lives of Daniel and Johnny from The Karate Kid. In this show, Johnny is indeed portrayed with more sympathy than he is in the original film. However, How I Met Your Mother did more than just predict this new TV show; also played a small role in producing the show in the first place.

In a 2020 interviewCobra Kai co-creator Josh Held credited How I Met Your Mother with keeping The Karate Kid in the public consciousness, helping to prove that a television spinoff could indeed be profitable. As he explained:

"We definitely appreciate the parallel fans that this show has, whether it's the 'How I Met Your Mother' story - which was amazing - we get asked all the time about the YouTube video if Daniel was the real bully... All those things just a little bit it encouraged us when we were imagining the show and comparing the stories to show the show because it made us feel sure that we weren't the only ones and we I didn't think we were but my it was nice to see other creators keep The Karate Kid in mind."

"Cobra Kai" was originally greenlit by YouTube Red in 2017, just a few years after "HIMYM" ended its run with (underrated!) series finale. While the show technically has nothing to do with the hit CBS comedy, it's funny to watch and think about how Barney Stinson would probably like it. Or maybe now that Johnny is portrayed sympathetically, Barney may feel betrayed and start to turn against him. It's hard to say for sure; All we know is that Zabka himself is grateful for what "HIMYM" has done. Neil Patrick Harris recently interviewed the actor for his websitewhere Zabka explained how big of a deal "HIMYM" is to him.

"After decades of being cemented in pop culture as an '80s bad boy, fans suddenly sympathized with me and even cheered for me," Zabka explained. "All the love and goodwill I felt from that has continued to this day and certainly added fuel to the Cobra Kai fire!"