Paapa Essiedu cannot sit still. When we meet in a tiny attic space at the RSC's London rehearsal rooms, the actor is like a human-sized dynamo. He stretches out his legs, he sits sideways on a chair, he stands up and sits down, he hugs his knees to his chest. He moves constantly. And that's just in the first five minutes. There's a restless, roving exuberance to Essiedu. And it makes you wonder whether it's all going straight into his latest role: the troubled prince Hamlet.

The answer to that is: perhaps. "Hamlet demands an enormous investment of your own personality," Essiedu says at one point during our interview. Which could mean his Hamlet is one of the most hyperactive we've seen. But other than that fairly vague statement, Essiedu won't be drawn on how he's going to approach the Dane. "If I told you," he says, smiling "you wouldn't come, would you?"

But he does reveal that Simon Godwin's RSC production will be in modern dress: "It's going to be very now, obviously we're still in Denmark and Elsinore, but we've taken on loads of influences from the whole company. You won't have seen the play performed in the world we're performing it in."

One thing that we can also safely say is that, unlike some Hamlets you may have seen recently, this production won't be a star vehicle. The main reason for that is that the 25-year-old Essiedu is a relatively little-known name. He's worked on London's fringe theatre scene, once at the Royal Court and he's been part of the RSC's company in the past. Hamlet will be Essiedu's most high profile role to date.

"I hadn't learnt my lines and I thought: Oh my God this is going to be the end of my career"

That's not to say he hasn't already turned heads. In fact, he's already managed to hit headlines. In 2014 he was the understudy for the role of Edmund in Sam Mendes' King Lear at the National Theatre. And half way through one performance he was called upon to do his acting duty. Luckily, prior experience meant he was fully prepared. "The last time I was at the RSC I was understudying someone – it was a girl actually, we were doing a cross-gender play – and there was this one night where no one knew where she was. And I hadn't learnt my lines," he says. "I thought: Oh my God this is going to be the end of my career and I've only just graduated from drama school!"

The actress turned up with two minutes to go and Essiedu learnt his lesson: he vowed that never again would he put himself in that position. So when he had to step up a year later, Essiedu was ready. Eye witness accounts confirm that he was tremendous.

From Walthamstow in east London, Essiedu was planning on being a doctor. He applied to do medicine at UCL, but quickly realised – when faced with the prospect of six more years ‘at school' – that it probably wasn't for him. It was during a subsequent gap year that he began to act and joined the National Youth Theatre. "It was the first thing that I did because I enjoyed it," he says, simply.

It's impossible not to like Essiedu. Throughout our interview he's a cheeky, laid back presence: he jokes, belly laughs and mocks. And he is keen to downplay the importance of this role on his career. "It means everything because it's a dream of many young actors to play a part like this in a place like this," he explains. "But absolutely not do I think about it as a seminal moment in my career because then that's the end of my career." I think it's fair to say he's also prone to exaggeration.

When I ask who he'd like to work with, he reels off names such as Ivo van Hove and Benedict Andrews. And you can see he's genuinely stoked to be spending his time with Simon Godwin, who he says is ‘great', and the rest of the company.

Read our review of Hamlet here

Paapa Essiedu in Hamlet
Paapa Essiedu rehearsing Hamlet
© Manuel Harlan

Essiedu seems to have taken this mega role – one of the biggest challenges that an actor can face – in his stride. Is he not even a little worried? "I think I'd be a fool if I wasn't nervous," he says, "But I feel in safe hands with the company. It's a company piece, so as much as the play is called Hamlet, the pressure is spread amongst all of us." That's a nice theory, but even Essiedu backtracks slightly after I look at him with an arched eyebrow: "I say that now but on the first night I'll probably be crying in the wings."

In total he has seen five versions of Hamlet, including Benedict Cumberbatch's ("I thought he was brilliant"), which Essiedu watched knowing that he would soon take on the same role. But, he insists, this version will be a totally different experience. "Benedict is this enormous superstar and Cumbermania was everywhere," he says, "that just won't be the same with this production." I'm not so sure: give it time and the world might just get on board with Paapamania.

Hamlet runs at the Royal Shakespeare Theatre from 23 March to 13 August.