The fame from TV's Prime Suspect was useful; the glory from her Oscar-winning turn as The Queen was gratifying.
But if only those projects could have helped Helen Mirren realize her lifelong goal. For that, she had to make National Treasure: Book of Secrets, which opened Friday.
"My ambition, in film, has always been to fly on wires," she said from New York. "In this film, I got to do that. Finally! I was so excited when I was told that would be a part of the movie, me in a harness.
"I did this movie for the fun, the fun of flying across a canyon, or standing in this huge pyramid chamber while the greatest technicians in the world filled it with water all around you. For two weeks! That's fun!"
She has been in big movies before - The Mosquito Coast, 2010, for instance. And Excalibur, she is quick to point out, "had every film person in Ireland" on the payroll. But that's peanuts compared with a big Jerry Bruckheimer action franchise.
"This is much bigger than anything else I've ever worked on," she said. "A week on National Treasure was probably the whole of The Queen's budget.
"But it was all just exciting and new, to me, at least. I was like a kid in a candy store. I was a bit nervous at the scale of it, because I wasn't quite sure what the pressures would be. You know, all that money being spent. Every day. Then it turns out that it's one of the least pressure-filled productions I've ever worked on. Jerry Bruckheimer is supportive and gentle - with the actors, anyway - who work on his movies."
The fun for Mirren extended to the movie's topic.
"I loved the way it brought the whole concept of history alive for kids," she said. "You know, it wasn't mean-spirited. It struck me as joyful and smart. And I enjoyed it. What more can you ask for from a film?
"What I love about the movies is they combine academically researched historical truths with complete fantasy. In a way, watching National Treasure is like its own treasure hunt. You're working out what's true and what isn't. I love the idea of bringing kids the realization of how lively history can be. It's not just a lot of dead people. These people were as alive and as interesting as we are today."
She should know. She has played enough historical figures - three queens of England; Morgana, temptress to King Arthur in Excalibur; Caesonia in the infamous historical porno Caligula. In Treasure, Mirren plays an ancient languages and American pre-history expert.