That's the thing - you do a job like 'Shameless,' and suddenly that's why you can get a job like 'The Virgin Queen', not because of all the classical theatre you've done. But we can be very snippy about television. It's absolutely the most potent and powerful form of storytelling we have.

For actors, being successful is generally getting a job. If you can work a lot, you're really successful. If you work a lot on projects that are interesting and intelligent and great fun to be part of, then you're hugely successful. And I feel hugely successful. I can't believe that I get to be involved with the projects and the people I work with.

The experience of having a child does crack you wide open. I felt like I suddenly had to rebuild the skin that I'd grown over the years before having a child. Perhaps that might be quite interesting in terms of acting.

I think age is sometimes just a number. But it's a real joy. Young actors don't come with any of the baggage that we load ourselves up with. They're not worried about their profile, they're not worried about how good they look, or all the nonsense. They just tell the story and ask: "What happens in this scene?" Well, I'll do that then. And professionally it's good for you because it means that you're forced to do the same thing, and that's always a good thing.

There are some roles you just don't say 'no' to. Those compass points: you get them so rarely as an actress.

In theatre, there's the director, the writer, and below them the actor. In film, it's the actors who are most important. That goes against the grain for me.

I suppose it's whether you want to be a famous person, or whether you want to be an actor. You have to decide what your priorities are. Great actor, huge star. Sometimes, the two walk hand in hand. Most of the time, they don't.