And there are times when he can’t believe what has happened.
“Up until I started this – let’s be honest – ridiculous job that I’m doing now, I’ve always just acted in things,” he says.
That ridiculous job is of course his hosting role on The Late Late Show, a coveted gig he scored in 2015 when most people in America had no idea who he was.
It catapulted him to the A-list, from an actor best known in his home country for Gavin & Stacey and The History Boys to major Hollywood player, and host of both the Grammys and the Tony Awards.
Since then, his acting has rather taken a back seat as he meets the demands of hosting an American nightly chat show, so he was excited to flex those muscles again to voice Peter Rabbit in the first live action film about the beloved Beatrix Potter character, which also stars Domhnall Gleeson and Rose Byrne.
“Even though you’re in a sound booth somewhere, you’re still engaging as a character somehow and working with a director and that’s the stuff that I really miss.Any chance I get just to dip my toes in that water I just jump towards, because creatively, it’s something I need.”
And taking on the role of the childhood favourite felt like a breeze compared with the huge amount of pressure he faced when his US TV show started.
It might be the first time in history someone has taken comfort from the possibility they could get the sack.
“I didn’t feel as much pressure with this because Peter Rabbit is this rabbit and he just needed a voice for a little while.
“So I just lent my voice and I did it safe in the knowledge that I could be fired at any point.
“It wouldn’t be that great an expense for a film studio, so that is actually quite liberating. You go in thinking, ‘They could just get someone else, so I will just try my best’.”
When we meet, Corden is fresh off a plane from Los Angeles, where he films the show and where he lives with his wife Julia and their three children.
He is also a partner in production company Fulwell 73, which makes The Late Late Show’s spin-offs based on its most popular segments Carpool Karaoke and Drop The Mic, as well as a string of documentaries and scripted offerings.
It all sounds exhausting but he looks remarkably fresh faced and certainly younger than his 39 years.
As we chat, he is sipping from a lurid orange drink, which is foaming wildly and might be fuelling his bounding enthusiasm.
He looks at the glass thoughtfully. “I’m not sure what it is. It’s not fruity, it’s caffeine. They give it to me.”
It’s impressive he has energy at all, given he is a father to young children (son Max is six and daughter Carey is three, baby Charlotte was born in December), but he is excited about sharing Peter Rabbit with his brood.
“This one is certainly the biggest thing that I’ve done that they would watch and we went to see the film and they absolutely loved it.
“I think they loved it regardless of my involvement. I don’t even know that my daughter, who is three, quite understands how it works.
“She knows it’s my voice but the animation is so brilliant in the film – the fur, the way it moves, the way the animals move, is so great – that even I don’t really think of it as my voice.
“I just think, ‘Oh he’s a rabbit and he needed to borrow a voice and he’s just used mine for this film’.”
Like most British children, he grew up with the classic stories, and they gave him an early taste for mischief.
“The overwhelming thing that I remember was, it was the first time I was read a story by a grown-up where the main character was naughty, where he was mischievous.
“I remember thinking, ‘This is amazing, they have actively told him not to do that and my mum is telling me that he did it anyway’.”
Corden denies he is as naughty as Peter, but he certainly has an appetite for pranks.
“I guess I’ve always had a glint in my eye but it’s not really for mischief, it’s mostly just fun.
“What I’m into is fun, I’m into a fun experience. I don’t see the point of much of it unless we are trying to at least have a laugh on some level. I guess there are some similarities to what I was like when I was at school.
“I don’t know if I was a ringleader but I was more like, ‘Imagine if you went and hit that fire alarm...’
“They would go, ‘Why don’t you do it?’ and I would say, ‘No, I think it won’t be as much fun as if you do it’. There was a lot of that.”
And while he lives thousands of miles away now, he still feels as English as ever.
“My favourite thing is our history and heritage and I know that sounds like a boring answer, but since I’ve moved to America that actually becomes more and more important to me, our sense of history, our sense of culture.
“We have this great heartbeat of history and I hope we don’t ever lose that.”
Peter Rabbit (PG) is released in cinemas the UK today.