The `Blue Valentine` star yearned to be a boxer when she was growing up and dreamed of lacing up the gloves and taking on the former heavyweight champion of the world.
She said: "First I wanted to be a boxer. I don`t know why but I wanted to fightMikeTyson. That was the dream."
However, Michelle quickly realised her pugilistic ambition would not be fulfilled and turned her focus to acting.
When she was 15 she emancipated herself from her parents after they disapproved of her career choice and the blonde star left school after completing the ninth grade and moved away from Solana Beach, California, to star in teen drama `Dawson`s Creek`.
Recalling her decision, Michelle told Stylist magazine: "I started doing plays when I was eight. I always wanted to act. At 16, I moved away to Los Angeles. [Emancipation] is basically like divorcing them. You have to prove that you are emotionally and financially stable and independent. You have to have graduated high school and you have to prove that you can live alone.
"I did one commercial at first every six months and that was enough."
The 30-year-old actress is now enjoying a successful film career - which includes her taking on the role of screen icon Marilyn Monroe in upcoming movie `My Week with Marilyn` - and she insists she still has a strong work ethic.
Michelle - who has a five-year-old daughter Matilda from her relationship with the late Heath Ledger - said: "I think hard work makes good people. That`s one idea I inherited from my upbringing and decided to stick with. I think it`s meaningful to do tasks yourself and to understand how your life operates."