‘There’s you, and there’s Frodo, and the Fonz. Then there’s Stan Lee, God rest his soul, and Hulk Hogan. Then there’s the Power Rangers in the corner.” Paul McGann is just back from Pensacon in Florida, where his status as the eighth Doctor Who means he has once again been sampling the surreal pop-cultural pleasures of a massive fan convention.

“With Doctor Who, there’s so much to talk about, years and years of it. You’ll see somebody to whom it really matters; it helped them through something. You end up sitting them down, just being kind to them. Give them a couple of minutes. Those conversations are really touching. You’re reminded of the power of stories and myths and heroes, and how people invest in all of it.”

A little less obviously heroic – but just as likely to get him stopped by a worshipper in the street – is his role in the 1987 cult comedy Withnail & I. Once, at a party in the Irish embassy in London, a person tapping him on the shoulder and asking for the “perfumed ponce” turned out to be the former Taoiseach Bertie Ahern. “It’s an ice-breaker,” he says of the film today, having long since given up any weariness over its legacy. “Richard E Grant and I were green and cheap. That’s how we thought you did pictures. We were naive because now there’s no time or money to rehearse pictures. We rehearsed for four or five days, and we learned it like a stage play.”

Making a movie was always McGann’s aim. He was born into a large, Irish family in Liverpool in 1959; when he got into Rada aged 17, quitting work at a local shoe shop, he had “never been to the theatre before. Some working-class kids went to the theatre; we didn’t. Most of us were there because of pictures and telly,” he says.

On TV, he lapped up the likes of I, Claudius, which gave him early career ideas. “I remember asking my dad, when it was on: ‘Is that a job?’ And he goes: ‘I don’t think they’d be doing it for nothing.’”

He would bunk off school to watch early 70s Hollywood indies such as Klute, The Last Picture Show and The Last Detail. Jack Nicholson was an early influence, but his real awe is reserved for memories of Karen Black, Nicholson’s co-star in Five Easy Pieces. Further back, he praises the versatility of Cary Grant, Dirk Bogarde and a less familiar name, the silent star Osgood Perkins, father of Anthony. “A brilliant actor,” says McGann. “One who didn’t give it away. He could just keep still.”

Still from L’Homme du Large. Photograph: The History Collection/Alamy Stock Photo

As a child, McGann got hooked on silent film through Bob Monkhouse’s compilation shows in the 60s; after he moved to London, he sought out screenings of more esoteric fare. He first saw Charlie Chaplin’s The Gold Rush at the behest of the director Bruce Robinson, when they were shooting Withnail.

In 2003, he acted in a short dialogue-free film called Listening, directed by Kenneth Branagh and co-starring Frances Barber. “It took us three, maybe four days to shoot this thing,” he says. “Me and Frankie had to meet for the first time, fall in love, with no words. Suffice to say, we found out for ourselves what we really only guessed at before, how good silent actors were, the very good ones. The ability to do complex scenes, shifts and nuance, with no words. Sadly these days, it’s a bit of a forgotten art. And it exhausted us.”

This month, McGann will lend live narration to a heartbreaking early film by the French director Marcel L’Herbier in a 1912 vintage cinema by the Firth of Forth. L’Homme du Large (1920) is the story of an ageing Breton fisherman and his troubled, possessive relationship with his son. Even the captions for the film are little works of art, with French text arranged in sharp geometric designs. McGann’s voiceover does away with the need for subtitles and adds to the film’s broodingly melancholic atmosphere. When he and the musicians performed L’Homme du Large at the San Francisco silent film festival last year, the effect was mesmeric.

To be both an advocate for and an all-too-rare practitioner of silent cinema is a curious second act move, but one which seems to suit McGann, now 60. In 2012, he performed excerpts from the lecture that would accompany South (1919), the film of Ernest Shackleton’s disastrous Antarctic voyage, and the boniment (commentary) for Georges Méliès’s Robinson Crusoé (1903).

The appeal for him, says McGann, is the live experience. “It’s a lovely feeling rehearsing with the musicians. You just fly by the seat of your pants; they’re like jazzers.” As well as the opportunity to share the bill with his (long-dead) heroes.

“So many of the actors from 90, 100 years ago, leave you standing. They’re actors’ actors.”

Paul McGann performs live narration to L’Homme du Large at the Hippodrome silent film festival in Bo’ness, west Lothian, Scotland, on 22 March.