Nine years can be a long time in an actor's life - particularly for one who's gone from just starting out to being a household name in that time - but Eddie Redmayne is still pinching himself about filming scenes for a movie that came out almost a decade ago.

"I'll never forget arriving on set on the first day, for the [2006] film The Good Shepherd, where I played Angelina Jolie and Matt Damon's son," says the boyish-looking 32-year-old, smartly dressed in dark trousers, grey jacket and navy jumper. "Going, 'I don't know what's going on here! When are they going to find me out? Get me out of here!'"

These days, of course, Redmayne is just as likely to pull in flocks of film fans as his one-time screen parents.

Indeed, he is having something of a 'moment' himself. Keen to keep his private life just that, he isn't about to spill the beans about his personal relationships, but you'd imagine his recent marriage to long-term girlfriend Hannah Bagshawe, at Babington House in Somerset, was an incomparable high.

Professionally too, Redmayne, who grew up in London, is going from strength to strength.

He attended the prestigious Eton and studied the history of art at Cambridge, before really setting his sights on an acting career.

His first role was a workhouse boy in a school production of Oliver and, following the aforementioned Jolie film, his breakthrough came in the 2008 BBC adaptation of Tess Of The D'Urbervilles. Next up, his portrayal of a lowly film set worker, who witnesses the tense relationship between Marilyn Monroe and Sir Laurence Olivier during production on The Prince And The Showgirl, in My Week With Marilyn, further cemented his position as a promising talent.

But it's now, with his performance as Stephen Hawking in moving new drama The Theory Of Everything, that Redmayne is really coming into his own.

He's already been nominated for the London Film Critics' Circle and Golden Globe gongs for best actor (news he toasted with a mulled wine), and there's talk of an Oscar nod too.

Spanning Hawking's life, from his days as an able-bodied Cambridge graduate, being diagnosed at the age of 21 with ALS, a form of Motor Neurone Disease, and given just two years to live, to the revered scientist he is today, The Theory Of Everything isn't a straightforward biopic.

It shows the incredible budding relationship - and later marriage - between Hawking and his fellow student Jane Wilde, played by Felicity Jones, who has also picked up a raft of nominations for her performance.

Sacrificing her own career, Jane, whose memoir inspired the movie, devoted her life to supporting Hawking and caring for their young children.

Discovering more about this unique and entirely universal love story left a lasting impression on Redmayne, who likes to spend his weekends going to art exhibitions.

"What I see is that Stephen and Jane had these incredible hardcore obstacles put in front of them, and rather than letting the obstacles or limitations define them, it was how they overcame them that defined them," says the actor, who also played Marius in the 2012 big screen version of Les Miserables.

"I took that as a message we can learn from. Even though it's a specific scenario for them, in life, we always have limitations and things put on us, and how we choose to overcome them is what defines us."

While the film could be saccharine, it doesn't gloss over the friendship the physicist and his wife had with widowed choirmaster Jonathan Hellyer Jones, portrayed by Charlie Cox, who Jane later wed. Hawking also remarried, to his carer Elaine Mason, played by Maxine Peake.

To prepare himself for the role, Redmayne met with other people who have ALS, watched countless clips of Hawking and learnt to isolate muscles in his face, indicating 'yes' with a "sort of smile" and 'no' as an "almost grimace".

"It was intense, but it was also quite riveting," he says of the rehearsal process. "It was interesting to really immerse yourself in that world... waiting for everyone to leave, sitting in front of the mirror and trying to learn to isolate those muscles he uses. It was complicated and different, but it was interesting."

He also met up with Hawking to discuss the role, which he admits was "terrifying".

"He had gone from iconic to idol status in my mind," Redmayne explains with a smile. "So when I met him, I was pretty terrified. I suffer from verbal diarrhoea. I hate silence, so I basically spent the first half hour telling Stephen Hawking about Stephen Hawking."

After overcoming his initial nerves and leaving with a sense of the acclaimed scientist's "humour, wit and his sense of mischief", the burden of expectation started to dawn on the actor.

"From the day I got the part, the weight of it, the responsibility, was unlike anything I had ever felt before," he explains, admitting that he lost sleep over the role.

And while Redmayne's awards shelf already boasts a Tony for his Broadway run as artist Mark Rothko in Red, he admits his radar for work can sometimes be a bit skewed.

"The thing is with films, I'm really bad at judging scripts," he says. "Because I've done scripts that I thought were great, and then you end up doing something that's kind of dodgy. And I've done scripts that are dodgy, that suddenly end up being interesting."

While the film has been attracting stellar reviews and awards hype, Redmayne, who says he would love to tread the boards again, is keeping a cautious cool about it all.

But it must be thrilling to hear you're tipped for an Oscar?

"Do you know what? I try not to listen to it. Because if you listen to the good stuff, you have to listen to all the bad stuff too," he says. "And that's actually where madness lies. So, I bury my head down and just put one foot in front of the other."

EXTRA TIME - FIVE EPIC SCREEN TRANSFORMATIONS

:: Daniel Day Lewis, My Left Foot (1989) - Method actor Lewis broke two ribs, didn't move from his wheelchair between takes and was spoon fed his meals to immerse himself in the role of Christy, who is born with cerebral palsy and learns to paint and write with his only controllable limb.

:: Hilary Swank, Boys Don't Cry (1999) - Swank won the Oscar for her role as a teenage American girl who takes on a male identity. To prepare, she bandaged her breasts, shoved a sock in her underwear, adopted a low voice and spent months introducing herself as a male.

::: Charlize Theron, Monster (2003) - While playing serial killer Aileen Wuornos, the South African star partially shaved her eyebrows, piled on weight and fried her hair.

:: Christian Bale, The Machinist (2004) - The actor dropped a whopping 60lb for his role in psychological thriller The Machinist, reportedly going on a crash diet before the cameras started rolling and shunning social events to avoid binge-eating.

:: Michael Fassbender, Hunger (2008) - In this unflinching film about the 1981 republican hunger strikes, Fassbender braved controversy and lost 14kg to play Bobby Sands.

:: The Theory Of Everything is released on Thursday, January 1