The 49-year-old actress is a self-confessed "theatre geek" and though she doesn't come from an especially privileged background, she doesn't think it's inhibited her career.
The London-born star shared: "I didn't have that sense of entitlement because nobody in my life had come from the world in which I now inhabit, but what I had going for me was a sort of unshakable self-righteousness.
"It's hilarious when I think back, but I was so passionate about being an artist, about being a storyteller and making change through stories. So I had that on my side, and I was a theatre geek."
Anne-Marie admits to having an idealistic approach to her career during her teenage years.
The actress - who was married to James McAvoy between 2006 and 2016 - told The Times newspaper: "I had this idea - which was perhaps a little dated by the time I was a teenager - that the power and the medicine of art had to be fought for.
"I was on my barricade, and that really helped me because it would have been very easy not to have kept going. The odds were stacked against me."
Meanwhile, Anne-Marie previously revealed she still has the "greatest bond" with her ex-husband.
The actress and James, 41, have remained close friends, and have both agreed to make their 10-year-old son Brendan their "biggest priority".
She said: "We have a son, we have the greatest bond two people can have - that for us will always be our biggest priority."
Despite this, Anne-Marie likened their divorce to "holding hands in a hurricane".
She explained: "Divorce is a profound, difficult experience. It just is.
"It's a bit like you go to bed and you wake up holding hands in a hurricane. And nobody gave you any storm warnings."