But it's a journey and the sad thing is you only learn from experience, so as much as someone can tell you things, you have to go out there and make your own mistakes in order to learn.

I used to look back at pictures and cringe but actually I'm quite proud that I've had fun with fashion and don't always look perfect. The only regret I have is when I look at something I wore when I was very young and it obviously looks like it belonged to someone else.

It sounds like a cliche but I also learnt that you're not going to fall for the right person until you really love yourself and feel good about how you are.

To be honest, I've always had far too much freedom. I had a job when I was 10. I started living on my own when I was 17 or 18. I've earned my own money; I've traveled the world. What would I rebel against? I've had so much freedom, sometimes it was hard. My parents wanted to protect me, but they had no idea how to. I had to learn as I went and make my own mistakes. I went from being totally unknown and never acting professionally to being in a major movie and being very famous. It all happened so quickly, I didn't have any time to work things out. It's been pretty scary at times.

Being asked to serve as UN Women’s Goodwill Ambassador is truly humbling. The chance to make a real difference is not an opportunity that everyone is given and is one I have no intention of taking lightly. Women’s rights are something so inextricably linked with who I am, so deeply personal and rooted in my life that I can’t imagine an opportunity more exciting. I still have so much to learn, but as I progress I hope to bring more of my individual knowledge, experience and awareness to this role.

It sounds so geeky, but I really do like studying and reading, and if I'm not working on 'Harry Potter,' then my greatest relaxation is to sit with a book.

People sometimes talk about me as being a brand, having a strategy and whatever else. I wish. Seriously. I wish I had it together enough to have a strategy. But it's so instinctual. It usually comes down to two things: the person I'm working with - the director is really important to me - and a line in a script.