The Hangover transformed Zach Galifianakis into an international star, but the 2009 hit film also left him "panicked".
Galifianakis was a successful stand-up comedian before making the movie but was genuinely worried his new-found fame would mean he wouldn't be able to sit in public and observe people, which is where he got the majority of his comedy material from.
"That's the challenge for a comic that gets a little bit of success, or a lot of success," Galifianakis tells Jerry Seinfeld in web series Comedians In Cars Getting Coffee.
"I felt quite intimidated after The Hangover. Not to be complaining, but I panicked because I thought — I got to sit and watch people, observe it. That's where I got everything. I got threatened that I wouldn't be able to do any more writing."
Seinfeld, who is one of the greatest stand-up comedians of all time, completely disagrees with Galifianakis' concerns.
"That's all your perception," Seinfeld says.
"The world has not changed that much because people know who you are. This whole thing that 'I can't observe the world now because I'm not anonymous,' I don't buy one bit of that. I don't. There's too much world."
In the hilarious episode of Comedians In Cars, it becomes apparent that the two stars have very different opinions on fame.
When Seinfeld reveals that he rides his bike around New York, Galifianakis asks, "Doesn't that bother you with people bugging you?"
"Nobody bugs me," Seinfeld says. "How would they bug me?"
He explains that if someone yells out at him he simply says "hey" back to them and then moves on.
Galifianakis also asks Seinfeld if he finds it rude when starstruck fans pull out their phones and start filming him without asking permission.
"If you're a well-known person, I think you gotta accept that," Seinfeld says.
"Really? What?" a stunned Galifianakis replies.
"I'm out in public. There's no privacy out in public. That's why it's called public," Seinfeld tells him.
"You're in a restaurant and someone's filming you there," Galifianakis says hypothetically.
"That's fine," Seinfeld says.
"Nobody's interested. Nobody cares. No one's gonna watch it.
"I don't see that as an incursion on my privacy or my dignity or I don't find it rude."
Galifianakis is one of 12 stars who Seinfeld interviews in the new season of Comedians In Cars Getting Coffee which is out now on Netflix. Some of the other funny people featured in the show include Ellen DeGeneres, Dana Carvey, Alec Baldwin and Kate McKinnon.