The 36-year-old actress – who has been married twice before - used to let her "ups and downs" affect how she felt about herself, but has now learnt to let go of things she is not happy with.
She said: "I'm not going to get upset the way I used to. Once you're in your 30s you learn not to panic or stress too much about work.
"You don't let the ups and downs of your career affect your sense of self-worth or personal well-being. That's probably the greatest lesson I've learnt from all of this."
The Oscar-winning star – who will soon be seen in cinemas in Roman Polanski's new movie 'Carnage' alongside Jodie Foster – is particularly happy with the direction her career is taking at present.
She told Britain's OK! magazine: "I'm very happy and I can't complain. I've had the chance to work on very good projects of late and work with very talented directors. I hope things continue that way."