Paapa Essiedu is a 34-year-old British-Ghanaian actor who moves seamlessly between stage, TV and film. Brought up in Walthamstow, north-east London, he trained at the Guildhall School of Music and Drama before joining the RSC. At 25, he became the first black actor to play Hamlet for the company. Essiedu was also Kwame in the 2020 BBC comedy drama I May Destroy You, created by his Guildhall classmate Michaela Coel. Next up, he stars in Death of England: Delroy, the second of Clint Dyer and Roy Williams’s state-of-the-nation trilogy of plays, which premiered at the National Theatre between 2020 and 2023 and are now being performed together in the West End. Essiedu lives in London with his wife, the actor and comedian Rosa Robson.

Delroy in Death of England is a seriously demanding role. You’re the only character on stage and it’s a 100-minute monologue that tracks the ups and downs of his life. Are you ready for it?
The challenge is enormous. I thought I’d done things that were demanding, played Shakespearean leads and even that play I did at the National last year [Lucy Prebble’s The Effect], there was a lot to it. But this is a different beast.

So this is harder than playing Hamlet?
Yeah, this is different gravy, mate. When you’re doing plays, there’s usually a moment where you’re feeling nervous or your concentration wavers or you’re thinking about what you’re going to have for dinner that night or whatever. You can have those moments either in between scenes or in a scene that you’re not in or even in a scene when the other person’s talking. However, with this, you can have those moments before the play starts and then after the play finishes. I haven’t found a thing in my life where I’ve had to have that level of concentration for that period of time.

I’ve read that you always like to put on your character’s costume a minute before you go on stage. Why is that?
That’s true – it’s really annoying for the stage managers. I hate to be wanky about that kind of stuff, but I want to save its impact for when I’m on stage, as opposed to walking around sweating and spilling ketchup on it, playing football or whatever. It makes you lose the magic a little bit.

And when you come offstage, you take off the costume and you’re not that character any more?
Yeah. Also I sweat profusely, I’m a big, big, big sweater. So really, that costume needs to come off im-med-i-ate-ly, immediamente, because it’s not really fit for purpose by about four minutes into the play. But you’re right, I’m not a big believer in taking your characters home with you. It works for some people, but for me it’s about a really, really intense, concentrated execution time so I can let it go afterwards. The rest of the time you’ve just got to be living your life, and that’s hard enough!

You’re co-starring in a new film, The Outrun, opposite Saoirse Ronan, out in September. She’s said about you: “He can do it all!” That must be a nice compliment to receive?
It’s kind of the pot calling the kettle black, really. Saoirse, she’s a magician. She’s one of those actors where, for real, I remember performing opposite her and being so enchanted by whatever this innate quality that she has that it made me forget what I was meant to be doing. Which is very embarrassing, to be honest. I’m not meant to be there as a fan. But she’s just that brilliant and we’re all so proud of the film.

You met Michaela Coel just before starting at Guildhall. Were you the standout stars of drama school?
Very much the opposite. If you spoke to anyone in our class or any of our teachers, no. But I can only really speak for myself: I was rubbish at drama school. I came to it late; I didn’t do any acting, really, until I was 17 or 18. So I knew nothing. I thought acting was essentially just shouting and pointing. And to an extent I guess it is, but I’ve added a few more strings to my bow.

You had a place to study medicine at University College London. Are there any parallels between acting and being a doctor?
I actually know a couple of actors whose side hustle is working for the NHS. Which is what my mum would have loved me to have done, but you can’t have it all. But the thing that always made me want to be a doctor is their capacity to say the right thing to people when they’re under huge stress. And actors – again, I want to veer away from any sort of woo-woo – need to understand the nuances of human emotion: what makes people laugh, what makes people cry, what provokes people. So in that way, it’s operating in a similar sphere, just maybe with fewer scalpels – unless you work on Grey’s Anatomy.

You seem to move very easily between theatre and screen. Is that the plan going forwards?
Every time I get any job, I go: “Jesus, what? Really? Me?” I didn’t grow up going to the theatre. I still remember the first play that I saw, which was Don Juan in Soho at the Donmar Warehouse, and I was just so blown away. It was so impactful to me as a 17-year-old and I still get that. But at the same time, television and film have the capacity to reach… I went on holiday to Brazil, to this tiny island, and we had to get this little dinghy boat from the mainland. And someone was talking to me in Portuguese about having watched this series I did called Press, which was about eight years ago and no one watched it. But they were raving about it and I was like: “What the fuck!” So I feel very privileged to have the opportunities to dip a toe into all those different warm baths.

• Death of England: Delroy is at @sohoplace, London, until 28 September