"I started out training with the builder as a labourer two years ago and now I'm doing it all myself," he says.
This is the actor's first stage outing since his well-received West End debut at the Garrick Theatre in 2010, playing a closeted film star in Douglas Carter Beane's comedy The Little Dog Laughed.
He still insists on skipping over any questions about Knightley; the two made a pact never to mention each other in interviews even when they were together.
He went on to play Lieutenant Kurt Kotler in the 2008 film The Boy in the Striped Pyjamas and Prince Albert in the 2009 film The Young Victoria with Emily Blunt.
He was plucked from London's Webber Douglas Academy of Dramatic Arts in 2004, to make his big-screen debut in a supporting role as Depp's lover in The Libertine. So it was a huge learning curve in front of one of the greatest screen actors ever.
I had the greatest teacher ever – even if he didn't know that."He met Knightley on the set of Pride and Prejudice a year later when he was playing Mr Wickham and was suddenly thrust into the paparazzi spotlight as the pair started dating.