Michelle Williams finds it hard to distinguish between her real relationships and her on-screen ones.

The 'My Week With Marilyn' actress - who has a six-year-old daughter, Matilda, with the late Heath Ledger - says her career can sometimes Blur into her personal life, leaving her confused.

Michelle - who starred alongside Ryan Gosling in 'Blue Valentine' - said: "When I look back on my life and I sort of reflect on relationships or anything, my mind folds that one into the mix of the real relationships that I've had in my life.

"And I have to stop myself and say, 'Oh, no, you did not marry and divorce Ryan Gosling.' "

While she sometimes gets confused with what's happened, the 31-year-old beauty says she is now comfortable in her own skin.

She told the New Zealand Herald newspaper: "One thing that I've struggled with, been interested in just as a person, a girl-slash-woman, whatever I am at 31 in this world, is being comfortable with myself.

"I've just spent a lot of time getting to know that person and getting to like that person, so I haven't wanted to lose touch with that person through lenses like hair and make-up and clothes."