Despite his strong ties to Kreese (Martin Kove) and his dojo, Johnny (William Zabka) didn’t recognize Terry Silver (Thomas Ian Griffith) in Cobra Kai season 4. With Silver being Kreese’s best friend and the co-founder of the dojo, it was surprising to some that he’s never crossed paths with Johnny, especially since the latter was once so important to Cobra Kai. While representing the dojo, Johnny won the All Valley Karate Tournament twice during his high school years and lost to Daniel LaRusso (Ralph Macchio) during the finals of the 1984 tournament.
Due to Silver’s scheming, Johnny’s opponent was forced to return for the 1985 tournament where he had to face a Cobra Kai student in the finals for the second time. Though Silver went through a great deal of effort to ruin Daniel’s life and restore Cobra Kai’s image, he ultimately failed to achieve his goal when Daniel managed to beat Mike Barnes (Sean Kanan). Though Daniel won, he didn’t forget the emotional and physical torture he endured at Silver’s hands. His resentment toward Silver was on full display in Cobra Kai season 4 when the Karate Kid Part III villain showed up at the Miyagi-do dojo alongside Kreese.
Unlike Daniel, Johnny didn’t have much of a reaction to Silver, considering that he didn’t know the character. Later on, Daniel had to catch him up on the events that took place in The Karate Kid Part III. Even though both Johnny and Silver are major figures in Cobra Kai’s history, Johnny not knowing Silver makes sense. He graduated high school after his loss to Daniel and got out of Cobra Kai. Angry with Kreese over his treatment of him, Johnny didn’t reestablish his connection to Cobra Kai until the beginning of the series when he re-opened the Cobra Kai dojo in a strip mall.
As for the time that Johnny spent in Cobra Kai during the early 1980s, it can be assumed that Silver simply wasn’t around. Presumably, Silver was busy with his business ventures and hadn’t actively taught Cobra Kai in years. The beginning of The Karate Kid Part III gave the impression that Kreese and Silver hadn't seen each other in a long time. Also, it’s worth noting that the idea of Silver not having a presence in Johnny’s life is consistent with a reveal from Cobra Kai season 1. When Johnny was making a case for the tournament’s ban on Cobra Kai to be lifted, the committee brought up Terry Silver’s actions in 1985. This prompted Johnny to say that he had never heard of this person.
Johnny went into Cobra Kai season 4 without any firsthand knowledge of Silver and his underhanded tactics, but it may not be long before he gets a sense of who he is and what he’s truly capable of. Silver held himself (and his students) in check for much of the season, but he began to revert back to his old ways as the tournament grew closer. Silver framing Kreese for the beating of Stingray (Paul Walter Hauser) and paying off a referee show that he’s given up on doing things differently. Depending on what Silver will be up to in Cobra Kai season 5, Johnny may get a taste of just how dangerous and psychotic the character can really be.