"I looked down, and [Jamie Foxx] was laughing, and it just put me at ease," Jon recalls. "If Jamie's laughing, this is going to be okay."
As the host of Comedy Central's Daily Show, Jon says he feels more pressure from his own audience of non-celebrities.
"[Jack] Nicholson, I'll never see that dude again. You know what I mean?" Jon jokes. "If he hates me, it's like, 'Okay, see you in the movies, buddy!' But for your own audience, I think you feel more responsibility."