Carey Mulligan recently realized that she’s spent much of her professional career holding back.

That might be surprising to hear for an actor with two Oscar nominations, a Tony nod and a laundry list of extraordinary films and enviable roles. She just didn’t get precious about it and preferred the old Laurence Olivier adage “why don’t you just try acting?”

But that changed in the past several years, in no small part because of Bradley Cooper and “ Maestro,” an all-encompassing project that would push her out of that comfort zone to play Felicia Montealegre, the elegant actor and wife of Leonard Bernstein.

As with “ Promising Young Woman,” “Maestro,” now streaming on Netflix, would prove to be a transformative experience for her understanding of herself as an actor and what she’s capable of. And it’s likely to earn her another Oscar nomination and possibly her first win.

Mulligan spoke to The Associated Press about the journey to becoming Montealegre, and the people who helped her get there.

THE VOICE

Mulligan had become used to only ever getting a few months of prep for most of her roles. Suddenly she had years, which was both wonderful and daunting after Cooper approached her about the role in the summer of 2018. In addition to learning everything she could about Montealegre and even giving herself over to “dream work” with Cooper, she immediately got to work studying her character’s unique dialect. Montealegre was born in Costa Rica, raised in Chile in a multilingual household and educated at British school in Santiago.

Luckily, there were long recorded interviews which Mulligan listened to over and over. She also worked closely with famed dialect coach Tim Monich, who had actually met Montealegre once.

“She was just as you see her in the Murrow Person-to-Person interview. I was a rube-ish 26-year-old and I had never met anyone as easy, relaxed, and elegant as she,” Monich wrote in an email. “In a room with her, what a voice. And Carey has that, too… Carey’s voice is one of her glories, and over quite a few roles we have played and altered it for different characters.”

His process, Monich wrote, includes something he calls Language Lab, “in which we listen to the real voices and then imitate them, riff on them, and play with them until they are the actors’ ‘real’ voices, too.”

Mulligan and Cooper would often meet and just talk as the characters so that by the time they got onto set they wouldn’t have to think about it which proved especially helpful for their epic Thanksgiving argument.

THE PAINTINGS

Felicia was a painter and Mulligan was not. An earlier script included scenes of her painting on camera, and Mulligan promptly signed up for a few months of classes. During a bout of COVID-19, in which she found herself quarantined in Santiago after having visited Montealegre’s extended family there, she asked Netflix to send her an easel, paints and canvas and would spend the next 10 days copying her paintings.

Though the scene didn’t end up in the movie, her paintings did. Kind of. Mulligan laughed that production designer Kevin Thompson put them in the “deep, deep background.”

“They were dotted around the set. I don’t know if you can see any of them though. To be honest, they’re not very good,” Mulligan said. “And the one that is in the hallway is NOT me. That was original Felicia.”

THE LOOK

“Maestro” spans decades and would require Mulligan to play her from age 24, in 1946 when she met Bernstein at a party, to her death in 1978 at age 56. Hair and makeup would thus have to make Mulligan, 38, look both younger and older as well as depicting her evolving, and famous, clothing and hair styles through the ‘50s, ’60s and ‘70s.

In the early scenes, shot in black and white and on film, she learned that costumes that pop in that format might not actually look great in real life — but Oscar winning costume designer Mark Bridges (“The Arist”) was proficient in both. Her favorite of the many looks, though, was probably the dramatic blue dress she wore for the performance of “MASS.”

“It was the best dress for walking away,” Mulligan said. “I was like, this is amazing because she just can’t bear to be there to watch him receive the accolades.”

It was an interesting experience seeing herself age, through makeup and prosthetics, too.

“I absolutely loved being in my late 50s. I don’t know why, I just thought, This is probably my sweet spot. Like, I think this is where I feel in my soul,” she said. “The makeup was so unbelievably real, but it sort of presents this slightly odd mortality crisis that you look at yourself go, well, this is exactly what I will look like if I ever got incredibly sick. It’s a little trippy.”

One time it even confused a doctor who had come to set to prescribe her some antibiotics and didn’t believe that she was 12-weeks pregnant asking her “are you sure” and “how do you know?”

“I was like why is this doctor being so weird? Then I looked in the mirror and realized oh, it’s because Sian (Grigg) and Duncan (Jarman) made me look 56 and it would have been a miracle baby,” Mulligan said. “I went to makeup and said ‘a doctor has just looked at me and thought I was in my late 50s. So kudos because that’s pretty good makeup.’”

THE CONNECTION

For Mulligan, a review that calls her “lovely” is just about the worst thing that a person can write. She was sad to learn that that’s exactly how most critics described Montealegre’s work.

“She got a lot of ‘she’s lovely’ and this sort of patronizing, mediocre, middle of the road reviews,” Mulligan said. “I just thought, oh, gosh, you know, to be married to Leonard Bernstein, who’s like touched by God and then get a review that’s like ‘she’s fine.’”

But something else resonated too. On one of the recordings, Mulligan said, “She was talking about the Actors Studio and she was saying she finds it just so embarrassing that these actors are throwing themselves around crying and telling all their secrets and pretending to be animals and how ridiculous.”

She has a theory that like herself, Montealegre was just nervous to fully commit because she didn’t want to fail. “Maestro” gave Mulligan the space to finally give herself over to it.

“She just never could quite do it. That really hit me.”