The flame-haired beauty - who has been nominated for an Oscar four times - did not intend to break into Hollywood and always thought she would be a doctor.
She said: "I didn`t have any intention of being an actress. I just did plays after school. I had a teacher who said, `Hey, you could do this,` and gave ma copy of Dramatics with all these schools I could go to.
And I thought, OK. Around that time, Meryl Streep was on the cover of Time. The story was all about the work she did in theatre as well as in film and I remember saying to my dad, `Look, do you see this person? She`s an actor!`
"My plan was to be a doctor. Even now I`ll think. `Why wasn`t I a doctor?` I would be helping people."
Despite not going into the medical profession, the `Kids Are Alright` star is glad she can help people through her various charity endeavours, including being the US ambassador for Save the Children. She said: "I was fortunate with the parents I had and the education and opportunities I got. "There are certain circumstances that a person can be born into where life is impossibly hard, but that wasn`t my experience. I feel I have an obligation and want to help others. After all, we live in one world."