The Trip's joy lies in wondering how much the on-screen "Rob" and "Steve" are like the real-life Brydon and Coogan. It works because we believe their relationship - all natural comic riffs, but also prickly, rivalrous and egotistical. It plays on their public personas: Coogan seems conceited; Brydon seems, well, affable. That he whinges about that persona is typical of the blurring of reality and fiction.
In person, Brydon is affable indeed: full of enthusiasm and praise (and the odd celebrity name-drop), but careful and cautious with criticism or complaint. He chuckles at himself and his success, but also gets properly upset at people who declare certain comedians are categorically "not funny". ("A ludicrous statement! There's no logic, no sense to it. Just say: 'It's not to my taste'.").
On the topic of family - he has five children, aged 2, 6, 14, 17 and 19 - he is genuinely utterly baffled when I suggest not every parent gets on with their teenagers: "Oh! Really? Well, I've been lucky. I adore them - they're the biggest thing in my life. I'm like a father to them!"
But if the Mr Nice Guy personality is grounded in reality, much of The Trip is invented. "Sometimes it's right on the money, it's exactly how I am; other times, not at all," explains Brydon.
"The one-upmanship, the voices, the undermining each other - that's a fiction. Because that would be awful."
Which is a relief, really. More surprising, however, is that the friendship itself is invented: Brydon and Coogan weren't pals when they shot the first series in 2010, although they had a long-standing professional relationship. And sorry, super-fans: you're unlikely to spy them doing their Michael Caine impressions over a Sunday roast in real life. "He's not one of my friends in the business I seek out," says Brydon, unsentimentally.
"In many ways we're very alike, in many ways, we could almost be brothers - and then in other ways, we're very different," he adds. "Obviously, comedically we have very empathetic rhythms, we have a chemistry and a shorthand. [But] he's very opinionated, sure of his view of the world in a way that I'm not. I know it annoys him that I'm so undecided about pretty much everything."
Yet the six-week shoot for The Trip to Italy may have drawn them together. Each night, Brydon and Coogan got to stay in the swish hotel where they'd been shooting, while the crew were packed off to more budget options. And the duo took to having another - unfilmed - dinner together each evening.
"Those meals were far more reflective, empathetic, warm affairs. In fact, at one, or I think two, we ended up in tears - talking about life, and the passing of time, our triumphs and failures."
Although Italy is sunnier than the damp Lake District, The Trip to Italy maintains the melancholic tone that developed during the course of their previous outing, and Brydon acknowledges that: "At its heart, it's a film about two blokes coming to terms with getting older and knowing that eventually they'll die."
For all that, though, The Trip to Italy largely props up Brydon's cheery public image - and it's one that certainly wins him work, from presenting the panel show Would I Lie to You? to the specially written role of Uncle Bryn in sitcom Gavin & Stacey.
When I ask if being Welsh has affected his comedy, he couldn't be more effusive, the accent suddenly springing up like a leek: "Ohhh, undoubtedly! Ohhh, entirely! You're the product of your gene pool and your upbringing, aren't you? Oh, yes. Oh, I'm Welsh, Welsh, Welsh."
Who: Rob Brydon
What: The Trip to Italy, his travel mock doco with Steve Coogan
When: Opens at cinemas on Thursday
- Independent
