Kumail Nanjiani initially viewed stand-up comedy as a "necessary evil" in his life.
The 44-year-old star began performing stand-up comedy at open-mic events after moving to Chicago - but he now admits it was a "miserable" experience for him.
Kumail - who was born in Karachi in Pakistan - shared: "I only got into stand-up because I wanted to write jokes. It was a necessary evil.
"I hardly performed before 9/11 and afterwards things suddenly shifted; I found being on stage miserable. People felt OK yelling racist stuff at me and it kept throwing me.
"I had to pre-write specific comebacks to take control so I wouldn’t lose the rest of the audience."
Kumail performed his stand-up routine on nights and at weekends while he worked at the University of Chicago.
And, at the time, Kumail didn't feel he had any alternative.
He told the Guardian newspaper: "It would take a lot of effort to not run away before every show but I felt I had no choice. There was nothing else that I loved that I also felt I could be good at, if I was given the chance."
The Hollywood star eventually quit his job and ultimately found it easier to be himself on stage.
Kumail said: "If you’re on stage being yourself and you don’t do well, the audience is rejecting you and your personal story, whereas if you’re playing a character, they’re just rejecting your persona.
"It took a long time for me to open up to that scrutiny in talking about myself. Just talking about a movie I liked took years."
Kumail's parents were initially angered by his decision to quit his job at the University of Chicago. But they're now huge fans of his movies.
The actor - whose film credits include 'The Big Sick' and 'Eternals' - said: "My parents watch everything I do. Thankfully, they get a kick out of it and they’re really proud. Once I started getting recognition, they stopped worrying about this being my career."