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.