Barry Keoghan has worked with everyone from Nicole Kidman to Colin Farrell.
However, the Marvel star admits he got seriously starstruck after a chance meeting with Dwayne 'The Rock' Johnson.
The Dubliner (26) met his hero at Disney's D23 Expo in California last month, and turned into a quivering wreck.
He said his girlfriend Shona Guerin had to make the introduction.
"They set it up for me, you know. I asked, 'Can I meet The Rock?' And they said 'Yeah'," he said.
"They say you shouldn't meet your heroes, and he was more than I expected.
"He was tired and ready to go, but he stood there with me and was willing to give me advice and I was the one who freaked out.
"I was like 'Oh, I can't, I can't, this is The Rock' and my girlfriend had to butt in and go, 'I just want to say, he can't talk but he is a huge fan of yours'.
"He was so loving, and the fact that he went and tweeted me afterwards and showed support goes to show that he's where he is because he's such a good guy.
"I'm watching all these people that I admire and getting to meet them, I'm starstruck that I get to meet half the people I meet. And I'm such a fanboy as well."
Johnson was obviously quite taken with the young star too.
He tweeted a link to the interview with him with the comment: "Barry liter- ally wouldn't talk to me, just kept walking in circles saying, 'No, no, no, no'.
"But we finally got our picture and shared some kind words.
"Great dude and I'm rooting for his success."
Keoghan was recently revealed as one of the big stars in the new Marvel movie The Eternals.
He will take on the role of a villain named Druig, whose traits include superhuman speed and strength, accelerated healing, flight and teleportation.
He joins a stellar cast that includes Angelina Jolie.
It's a busy time for Keoghan, as he has also landed the lead role in a new movie about the life of The Pogues frontman Shane MacGowan.