A comedian performed on the Tonight Show and got huge laughs. Then Johnny said something that made the entire studio go silent. Funny jokes. Too bad they’re all mine. It was September 1983 and Mark Sullivan was having the best year of his comedy career. At 32 years old, he was finally breaking through after a decade of struggling in small clubs and dive bars.

 Suddenly, comedy club owners were calling him. He was headlining at the comedy store in Los Angeles. He was getting standing ovations. People were saying he was the next big thing. There was just one problem. The jokes that were making Mark Sullivan successful weren’t his jokes. They were Johnny Carson’s jokes. Mark had started small.

 He’d watch the Tonight Show, write down Johnny’s monologue jokes, wait a few weeks, and then use them at small clubs in cities far from Los Angeles, in Tucson or Portland or Denver. Who would know? Johnny’s monologue jokes were topical about politics, current events, celebrities. After a few weeks, they felt like fair game, but Mark got greedy.

 As his reputation grew and he started performing in bigger venues, he started using more of Johnny’s material. Not just old jokes from weeks ago, but recent material. Sometimes jokes from just days earlier. He’d watch Monday’s Tonight Show and use the same jokes on Wednesday at the Comedy Store. The thing about stealing from Johnny Carson was that Johnny had a team of the best comedy writers in television.

 His jokes were crafted, polished, perfectly structured. When Mark used them, he sounded like a genius. Club owners loved him. Audiences loved him. Other comedians started noticing him. And that’s when the whispers started. In the tight-knit Los Angeles comedy community, people talk. Comedians watch each other sets. They notice patterns.

 And several comedians who’d seen Mark’s act had also watched the Tonight Show that same week. They recognized jokes, not similar jokes. The exact same jokes, word for word, set up and punchline identical. One comedian, a Tonight Show regular named Richard Lewis, was particularly bothered by it. He’d heard Mark do an entire five-inute segment that was beat forbeat Johnny’s monologue from three nights earlier.

 Lewis knew those jokes because he’d watched Johnny perform them. He’d laughed at them on Monday. Then on Thursday, he heard Mark Sullivan perform them like they were his own original material. Lewis thought about it for a few days. Calling out another comedian was serious business. But stealing material was the ultimate sin in comedy.

 It was the one unforgivable act. So Lewis made a decision. He called Johnny Carson’s office at NBC. I need to talk to Johnny about something important. Lewis told Johnny’s assistant. It’s about a comedian who’s stealing his material. The message reached Johnny that afternoon. Johnny called Lewis personally. Richard, what’s going on? Lewis explained what he’d seen and heard.

 He gave specific examples, jokes, dates, venues. Johnny listened without interrupting. When Lewis finished, Johnny was quiet for a moment. Then he said, “Can you get me a tape of one of his performances? I’ll make some calls.” 3 days later, a VHS tape arrived at Johnny’s office. It was from the comedy store recorded the previous weekend.

Johnny put it in his office VCR and watched Mark Sullivan’s 40-minute set. By minute 5, Johnny’s jaw was tight. By minute 10, he was shaking his head. By minute 15, he was furious. It wasn’t just a few jokes. It was wholesale theft, setup, punchline, timing, delivery. Mark had stolen Johnny’s voice, his cadence, even his physical mannerisms.

Johnny picked up his phone and called his producer, Fred De Cordova. Fred, I need you to book someone for me. Comedian named Mark Sullivan. I want him on the show next Thursday. Fred paused. Mark Sullivan? I don’t know that name. He’s performing at the comedy store. Tell him we saw his act. We’re impressed.

 We want to give him his Tonight Show debut. Make it sound like a big opportunity. Fred, who’d worked with Johnny for years, heard something in Johnny’s voice. Johnny, what’s going on? Just book him. And Fred, I want him to do standup. 5 minutes. Tell him to do his best material. His best material. Yes. His very best jokes.

 The ones that are killing at the comedy store. Make sure he knows this is his shot. Tell him to bring his agame. Fred understood. Oh boy. What did he do? You’ll see on Thursday. The call came to Mark Sullivan on Monday morning. His agent was screaming with excitement. Mark, Mark, you’re not going to believe this. The Tonight Show wants you this Thursday.

They saw your act at the comedy store and they want to book you. Mark’s heart nearly exploded. The Tonight Show. This was it. This was the dream. Every comedian in America wanted to perform on the Tonight Show. It was the ultimate validation, the career maker. If you killed on the Tonight Show, you could write your own ticket.

They want five minutes of standup, hisagent continued. They said to do your best material, your strongest stuff. This is your shot, Mark. Mark spent the next 3 days preparing. He put together what he considered his best five minutes. Jokes that had been absolutely destroying at the comedy store and the improv.

 He practiced in front of his mirror, refined his timing, got every beat perfect. What Mark didn’t know or didn’t care to think about was that every single joke in his 5-minute set had come from Johnny Carson’s Tonight Show monologues over the past 2 months. Thursday night arrived. Mark walked into NBC Studios in Burbank, feeling like he was floating.

 This was it. His life was about to change. Backstage, he ran through his material one more time. His hands were shaking with excitement and nerves. A stage manager came to his dressing room. You’re on in 10 minutes, Mr. Sullivan. Mr. Carson specifically asked for you to do your stand-up segment first tonight. He wants to make sure you get the best spot.

Mark felt a rush of gratitude. Johnny Carson was looking out for him. This was even better than he’d imagined. What Mark didn’t see was Johnny in his own dressing room reviewing notes. On Johnny’s desk was a printed list of jokes. Mark’s jokes on one side, and Mark finished his five-minute set to massive applause.

 The audience was standing. He’d done it. He’d killed on the Tonight Show. Mark turned toward Johnny, expecting to be invited over to the couch for an interview. The ultimate sign that you’d succeeded. Johnny was applauding too, standing, smiling. The applause continued for several seconds. Mark stood there, soaking it in.

 The greatest moment of his life. Then Johnny stopped applauding. He walked toward Mark, still smiling, but something had changed in his eyes. The studio audience’s applause began to fade as they sensed something unusual happening. Johnny reached Mark and put his arm around his shoulder in what looked like a friendly gesture. He took his own microphone and addressed the audience.

 “That was great, wasn’t it?” Johnny said. The audience applauded again, uncertain. “Really funny stuff,” Johnny continued. professional material, well-crafted jokes, great timing, great delivery. Mark smiled, not sure where this was going, but still riding the high of his performance. Johnny paused, his smile stayed in place, but his voice changed, became quieter, colder.

 “Funny jokes,” Johnny said, his arm still around Mark’s shoulder. “Too bad they’re all mine.” The studio went dead silent. Mark’s smile froze on his face. His brain couldn’t process what Johnny had just said. “What?” Mark managed to say. Johnny removed his arm from Mark’s shoulder and stepped back slightly, looking at him.

 The friendly warmth had completely left Johnny’s face. “Every joke you just performed,” Johnny said clearly, “came my monologues over the past two months. “Word for word, set up and punchline, you didn’t write a single one of them.” The audience gasped. Some people started murmuring. Mark’s face went from confused to pale to red. Johnny, I don’t know what your Johnny cut him off.

 August 15th, the joke about the president in the golf course. That was my joke from my monologue. August 22nd, the bit about the movie star in the restaurant. Mine. September 1st, the politician joke you just did. I performed that exact joke 6 days ago on this stage. Mark tried to laugh it off. Come on, Johnny. Sometimes comedians have similar ideas.

 These aren’t similar, Johnny said, his voice sharp now. These are identical. You’ve been watching my show, writing down my jokes, and performing them at comedy clubs like they’re yours. You’re not a comedian, Mark. You’re a thief. The audience’s reaction was visceral. Some people booed. Others just stared in shock.

 Mark stood there exposed with nowhere to hide and 20 million people watching from home. I I never meant to,” Mark stammered. But he had no defense, and he knew it. Johnny turned to the audience. Ladies and gentlemen, comedy is about originality, creativity, hard work, jokes, or intellectual property. When someone steals material, they’re not just stealing words.

 They’re stealing years of experience, craft, and effort. This man isn’t a comedian. He’s a joke thief. Johnny looked back at Mark. Get off my stage. Mark stood frozen, humiliated, destroyed. Johnny just stared at him, waiting. Finally, Mark walked off stage. No applause, just silence and scattered booze. He walked past the cameras, past the crew, straight out of the studio and into the parking lot. He never came back.

 Johnny returned to his desk and addressed the audience. I apologize for that, but it needed to be said. Comedy is built on trust. Trust that what you’re seeing is original, authentic from the comedian’s perspective. When someone violates that trust, they don’t deserve a platform. The audience gave Johnny a standing ovation.

 The incident spread through the comedy community within hours. By the next morning, every comedian in LosAngeles knew what had happened. The tape circulated. Bootlegged copies of that Tonight Show episode became legendary. Mark Sullivan’s career was over before it had really begun. The comedy store banned him. The improv banned him. No club in Los Angeles would book him.

 He tried performing in other cities, but the story had spread. Comedy was a small world, and everyone knew about the guy Johnny Carson had exposed as a joke thief on national television. Mark tried to apologize publicly, claimed he’d been influenced by Johnny’s style, that it was an accident, that he didn’t realize he was crossing a line.

 But nobody believed him. The evidence was too clear. The jokes were too identical. Within a year, Mark Sullivan had quit comedy entirely. Last anyone heard, he was working in sales in Phoenix, far away from any comedy club, far away from the industry he’d tried to cheat his way into.

 Johnny’s exposure of Mark Sullivan became legendary in comedy circles. It was a defining moment that reinforced the most sacred rule in standup. You don’t steal material. The consequences aren’t just professional, they’re permanent. Comedians still tell the story today. It’s used as a cautionary tale in comedy classes and workshops. Remember Mark Sullivan? They say, remember what happens when you steal jokes? The phrase, “They’re all mine,” became comedy shortorthhand for catching a joke thief.

 And comedians learned that in a world where intellectual property can be hard to protect, sometimes the best justice is public exposure. Johnny Carson didn’t sue Mark Sullivan. He didn’t need to. He’d done something far more effective. He destroyed Sullivan’s credibility and career on live television in front of 20 million witnesses.

 It was the ultimate demonstration that stealing from Johnny Carson wasn’t just wrong, it was career suicide. If this story moved you, please subscribe and hit that like button. Share it with anyone who needs a reminder that shortcuts and theft never pay off in the long run. Have you ever witnessed someone get caught stealing credit for someone else’s work? Tell us in the comments.

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