Cillian Murphy during his discussion with Margot Robbie for Variety's "Actors on Actors" series.YouTube, Variety

Cillian Murphy had a wide-ranging conversation with Margot Robbie for a new episode of Variety’s Actors on Actors series that was published on December 5.

Murphy and Robbie each starred in the biggest films of summer 2023 - “Oppenheimer” and “Barbie,” respectively - which gave way to the cultural phenomenon of 'Barbenheimer' after the two films opened in theaters on the same day.

In their nearly hour-long conversation, Cork native Murphy and Australian Robbie broached the topic of accents and dialects, with Murphy admitting he used a dialect coach for “Oppenheimer.”

“We weren’t trying to do an impression," Murphy said about portraying J. Robert Oppenheimer, "I can’t really - it’s not in my wheelhouse to do impressions, I don’t have that skill.

“With accents, for me, it’s like going to the gym for your mouth. It takes a long time.”

Robbie said “Australian mouths are like the laziest,” prompting a laugh from Murphy.

“It’s literally like a gym workout,” she said, agreeing with Murphy.

“But you guys [Australians] do Americans so brilliantly always,” Murphy said.

“Well that’s because we have to build the muscles in your mouth to do an American accent,” Robbie said. 

“Really?” Murphy said, intrigued, adding that he thought the accents would have been closer.

After Robbie explained the fascinating physical differences between how Americans and Australians speak, Murphy again said: “Aussies always do brilliant American [accents], I think.”

“Well, that’s good,” Robbie said with a smile, adding, “I love it when I hear that we have a good rep.”

“Well you certainly do with me,” Murphy said.

“The Irish have a great rep,” Robbie offered.

“Yeah, we’re not bad at it,” Murphy conceded with a smile.

Elsewhere in the conversation, Robbie asked Murphy about becoming a meme and his general understanding - or, rather, misunderstanding - of memes.

Back in 2017, Murphy was asked during an interview with NME if he was aware of the 'disappointed Cillian Murphy meme.'

"I don't - what's a meme?" Murphy asked, perplexed.

Of course, the moment turned into a meme itself.

Murphy told Robbie he now knows what memes are, thanks in part to his two teenage sons. 

"Now I know that there are memes about me not knowing what a meme is," Murphy told Robbie.

"It's a great meme," Robbie said, adding, "It's like inception of memes - a meme within a meme."

Laughing, Murphy continued: "I genuinely, at the time [in 2017], did not know. But people forget, that was a long time ago."

He added: "I think children started that stuff, right?

"But now that it's become this sort of like meme that's eating itself, I am aware, but it's mostly because people are sending it to me or showing it to me."

Asked if he saw any of the Barbenheimer memes, Murphy said it would have been hard to avoid it. The two agreed that the Barbenehimer meme phenomenon, which developed organically, could have never been conceived by the studios.

Towards the end of their chat, Robbie asked Murphy about his role as Tommy Shelby in the hit series "Peaky Blinders," which he described as a "ten-year adventure."

Robbie was keen to bring up the song that played at the end of the last season, "All the Tired Horses," a rendition by Irish artist Lisa O'Neill, noting that she has it on her "cry playlist" if she needs to cry on set.

"She's special," Murphy said of O'Neill.

Murphy went on to say that he would be open to the idea of a "Peaky Blinders' spinoff movie if a great script came his way.

You can watch Cillian Murphy & Margot Robbie in Variety's Actors on Actors series here: