James Corden was on a "quest" to not vomit on his clothes during his 'The Late Late Show' debut

He said: "You know so much that it’s a team from everyone - your wonderful band, everyone backstage, these incredible technicians, you’re absolutely in a team.

"So that’s what I was thinking - we’re all making this show together, and then just one night I found myself behind the curtain with all of these people who I thought were in it with me going, 'Hey, good luck man.'

"You look and they’re gone and you’re just on your own and all you can see is the spotlight from the back of the room on the curtain, just this circle, and you just go, 'Ah, this is going to open in a minute … and I’m going to have to walk out there and look remotely like I know anything about anything.' And then it’s just a quest to not throw up on your own clothes. That’s the truth."

James joked that he hasn't been recognised that much in the US yet as a security guard recently wouldn't let him into the 'Late Late Show' studio because he didn't have his pass - even though there was a huge billboard advertising his presenting debut on the programme in full view of the pair.

Speaking on 'Conan', he added: "I couldn’t get into the building the other day because I didn’t have my pass. Absolutely true story.

"I went out to get some lunch, picked up some lunch and I came in and I went to the guy, 'Hey man, how you doing?' and he said ‘I’m gonna need to see your pass, you got your pass?’ and I went, ‘Ah, no, it’s in there,' and so he went, ‘I’m gonna need to see your pass, man.'

"I went, 'No no no, I just left, I literally just walked out and I picked this up,' and he went, ‘I’m gonna need to see your pass,’ and I went, ‘Right ... it’s just because that’s … I mean that’s' …

"I went, ‘I mean is that not better that a pass in a way?’ That pass is so big I can’t fit it in a truck. And he looked at the thing and I went, ‘It’s cus...’ [points at his face] and he went, ‘I don’t see it man.' "

James eventually had to call one of his production team to come down and let him in.

Watch James Corden’s interview on 'Conan' at 1am Thursday March 26, on truTV (freeview channel 68).