Sat on a sofa in the Masters’ Lodge of Selwyn College, a glass of wine in hand, Alex Macqueen is explaining to me how he made the fatal error committed by many a Cambridge student.

“I’d always been fascinated by Cambridge,” he tells me. “I thought it might be the answer to all my life’s problems: I’d always work and I’d be sorted for life! How wrong I was!” he says with a laugh that only increases in volume when I point out most Cambridge students would consider the University to be the cause of all their life’s problems.

“The Inbetweeners is a whole new level of discussion. Every day there is some encounter on that front”

Arguably, too, Macqueen is doing himself a disservice: a man known up and down the country as ‘Neil’s Dad’ thanks to his role in The Inbetweeners is unlikely to be short of work. “I get a lot of offers for sort of dads who are slightly off-piste as well as nerds and weak characters,” he admits with a chuckle. However, Macqueen is adamant: “what I really want to play is evil villains. I’m having a dialogue with my agency at the moment about having to turn down stuff.”

“It’s difficult,” he tells me as I ask about his selection process for new projects. “You want to work – and you need to work – but sometimes you have to turn stuff away. Catherine Tate said once: ‘you’ll be defined by the work you turn away, rather than by the work you accept’.” He shrugs. “There are often adverts for millions of pounds, but you might potentially be defined by that campaign, so you need to turn it down.”

Logically, this may be true. Surely that ship sailed, though, when Macqueen became Kevin Sutherland? He laughs again, before confessing “The Inbetweeners is a whole new level of discussion. Every day there is some encounter on that front. I get it in all sorts of places – on escalators, I get a lot of ‘Bumder’ as I go past. Though in fairness, it’s a lot more of ‘Neil’s Dad’: people are a bit more sensitive than that.”

“I don’t begrudge it for a second,” he continues, explaining that “it’s a privilege to be recognised for your work.” That said, he does qualify this somewhat: “it does depend on what mood you’re in – if you’re in a happy and spirited mood, it’s great, but if you’re not really in the mood, it’s quite exhausting to then be ‘delighted’ to pose for a selfie.”

Wary not to ask too many questions about just one role, I allow myself one final question on The Inbetweeners, asking whether he always knew it was going to be a hit.

Shaking his head with a smile, he is quick to respond in negative: “I’d just come off The Thick of It, so I thought I was now only going to do high-grade comedy,” he laughs. “Truthfully,” he continues more seriously, “nobody had any expectations for it. It was originally a pilot called Baggy Trousers and after we did it, the actors playing four boys were let go because the chemistry between them was not quite right. And only one was saved: Jay [James Buckley]. And he had been playing Neil in the pilot!” He enjoys my audible gasp at this piece of information.

“A film is basically a series of photographs and, in some ways, it’s a technical exercise more than an acting exercise”

“It’s always very difficult to tell,” he continues. “I’ve done other shows where I thought ‘this could be a success’ and they’ve pulled it. And just look at the first The Inbetweeners film: that was a very big success out of the blue. It took everybody by surprise!”

Nonetheless, Macqueen has made a career of appearing in some of British comedy’s most successful shows, ranging from Peep Show and The I.T. Crowd to Plebs and even a voice actor role in a Doctor Who audio story. Attributing this impressive résumé to comedy being a “small pool”, in which writers contribute to numerous shows, he is – to my great delight – happy to talk about every single one of them in intriguing detail.

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After explaining that his character Julius Nicholson from The Thick of It was, to my great fascination, loosely “based, I believe, on Lord Adonis and Lord Birt” – though he notes that “after the first script was created, the writers were harvesting elements of our personalities and the way we deliver stuff to shape it” – he moves on to discussing his brief appearance in the cult classic Peep Show.

Noting the unique way in which the show was filmed – from the characters’ point of view – I wonder how difficult an acting exercise it was, given that acting is fundamentally reacting. After commending my knowledge of good acting practice – “acting is reacting,” he says, with a knowing smile that makes me feel warm inside – he explains that TV and film acting “often involves not really reacting to the other actors at all.”

“When I started acting professionally, I was very aware that the one thing theatre doesn’t do is pay very well”

“Instead,” he explains, “when the camera is on you – because eyelines matter so much – you’re sometimes acting to a piece of gaffer tape beside the camera.” He continues: “It’s quite a false and clinical environment in which to work. After all, a film is basically a series of photographs and in some ways, it’s a technical exercise more than an acting exercise.”

By this point in the interview, I notice that, while Macqueen has been exceptionally knowledgeable about the world of film and TV acting – offering enthralling insights into the filming of his low-budget film The Hide and joking about missing out on first-class flights to Australia with the rest of The Inbetweeners 2 cast – he has yet to mention life on the stage.

“I did the National Youth Theatre and that’s how I got into acting,” he explains. And during his time at Cambridge, he “did a number of plays for colleges” before setting up the Cambridge University Theatre Company. Noting my confusion at this, he laughs: “of course there’s the CUADC, but if you looked at the paperwork, there was still room to use the label and the crest and get sponsorship. So we did that and put on a play at the ADC. We did King John, which is an under-performed Shakespeare play, and had a lot of fun with it! We did the battle scenes as Tom and Jerry!” he says, his laugh laced with nostalgia.

But before long, Macqueen moved away from the stage. “I just got stage fright,” he tells me. “I got concerned about forgetting lines and being on stage. Also, when I started acting professionally, I was very aware that the one thing theatre doesn’t do is pay very well. It just can’t – the business model can’t sustain it. So I thought I must do TV because it pays better. And having done that for five to 10 years, I started to think, ‘I daren’t go on stage because I haven’t done it for so long.’”

Indeed, it was only last year that Macqueen finally returned to the stage, after 15 years on the proverbial wings. “I did a play with Kenneth Branagh and I was utterly terrified,” he tells me. “But I’m delighted I did it: it really did break a demon. Even on the occasion [I did freeze or forget lines] I managed to deal with it – it takes a huge amount for a big error to register in an audience.”

Macqueen attributes his short time as a barrister to helping overcome his fears, noting that the skills of “standing up in court in front of a judge and making sense even when you know you don’t know what you’re talking about” helped overcome “the terror when you’re standing in front of 300 crew and 400 extras and three movie cameras running precious tape that costs £10,000 an hour.”

“I wouldn’t want it to be that if you had a profile, you’d wouldn’t be able to engage in the national discourse”

As a Law student, I am intrigued by his brief stint at the Bar. Noting that he was always aware that “the acting world is unstable and capricious”, Macqueen explains he considered “the world of law is less so and was always keen to have a back-up.”

He smiles wryly when I point out the Bar is equally unpredictable. “There’s a lot of similarities,” he admits. “You’re self-employed, you rely on your agent/clerk for the brief/script, and sometimes you might not get paid for your job!”

Alongside acting, Macqueen is equally passionate about charity work and is in Cambridge to visit the laboratory of Selwyn College’s Dr Amer Rana. Enthusing about Dr Rana’s work for the British Heart Foundation, Macqueen tells me that he hopes he can work with the charity to “improve its engagement with younger people, given the BHF is [perceived as] a slightly elderly brand.”

After all, he points out, “heart disease spans all the ages. I’ve been exposed to people in their 20s who are suffering from heart attacks out of the blue – it’s much more prevalent than you might think.” He smiles humbly: “I guess that’s why BHF have got me on board to assist with the campaign. You know, because I’m off the telly.”

Laughing at his modesty, I wonder whether he has found – in the age where celebrities like Gary Lineker and Meryl Streep are being lampooned for daring to give a voice their views – that people are less prepared to listen to him.

“There’s nothing more bowel-clattering than hearing people be self-important about the views that they hold,” he responds. “But if you do use [your public profile] to highlight good things that might otherwise go undiscovered, then that’s a good thing, regardless as to how much it gets on people’s nerves. I wouldn’t want it to be that if you had a profile, you’d wouldn’t be able to engage in the national discourse.”

“I think it’s a lot easier with charitable activities,” he says with a chuckle. “I find it hard to believe that there are people who say ‘God, I wish Maggie Smith would shut up about Macmillan Cancer Research’.”

Alex Macqueen was visiting Cambridge as part of his work with the British Heart Foundation. Details of how to get involved with their work can be found here