IT'S GOT to the point where people recognise Rosamund Pike. Appearing in a Hollywood blockbuster will do that for a girl. "I was in Soho and this girl said 'oh, you look just like the lady from Gone Girl," Pike is telling me as you join us. "I said: 'I am her.' She just couldn't figure it out. How you could be buying cold cuts in Soho when you were on a cinema screen the night before. I thought: 'Gosh, this is a new thing.'"

It's not a bad thing, she adds. "There's a lot of recognition. Sometimes it's really nice. You feel like you can make someone's day by walking into their shop. I trick or treated with my son on Hallowe'en and one woman said, 'I've been waiting all night for trick or treaters and I've had no one. And then it's you.'

Well, it would be something, wouldn't it? A Hollywood star turning up at your door looking for Haribo sweets. Today we've only got sparkling water and fresh fruit in the Soho Hotel. Pike has had a day of it already, talking about her new film A United Kingdom. She is dressed in green and red, a slinky straight line of a woman, an Erte fashion sketch made flesh.

Pike is the archetypal English rose (though she does point out she had a Scottish granny). You imagine her as a head girl turned Bond girl. Her own self-image is a little different though. "I've always been a bit of an outsider although I probably seem to the outside an insider," she tells me. "But I've always been on the fringes of groups and now that's a position I really take ownership of and like."

How curious. She is 37 and the fact is she's been a regular on our screens since she made her film debut as said Bond girl opposite Pierce Brosnan in Die Another Day in 2002 (and that came after a handful of TV roles). She's done her share of costume dramas (Pride and Prejudice and The Libertine, opposite Johnny Depp spring to mind) and big budget spectacles (Doom and the first Jack Reacher movie, the latter alongside Tom Cruise, to name but two). She's also brought those blonde good looks to any number of minor movies.

Gone Girl was the game changer though. That was the one that made her a recognisable face to people serving in shops. And yet the David Fincher thriller was two years ago. Where has she been since, other than buying cold cuts and guising, you might ask?

"I did something quite odd," she admits. "To most people it might seem a crazy decision. I had the biggest moment of my career and I went off and hid away and had a baby. Most people would think that absolute lunacy when the whole world is suddenly interested in you and you put yourself off the market for a year and a half.

"But I tend to miss the most important moments of my career. I always seem to be somewhere with no cell phone reception when people are trying to get hold of me. When they wanted to recall me for the Bond movie I'd gone away to the countryside and left my mobile phone in London because we weren't attached to them then. I thought: 'No one's going to want me this weekend.' They couldn't get hold of me.

"Then when I got Gone Girl I was filming in Scotland [presumably making the film What We Did On Our Holiday] on the north-west coast and we had no cell phone reception. There were just lots of midges. There is a picture of me when the text came through in a midge net jumping."

Her post-Gone Girl absence is now well and truly over. A United Kingdom is the first in a series of films Pike has in the can. There's a wartime thriller HHhH due soon. She's made a film with John Hamm which will either be called Beirut or High Wire Act: another, Hostiles, a western with Christian Bale. And when we meet she's prepping to shoot Entebbe about the 1970s aeroplane hijacking in Uganda.

The roles are more interesting and more varied now, Pike says, and, perhaps more importantly, she says she finally knows what she's doing. That's very clear in her latest film in which she is a wonderfully warm, even joyful presence.

A United Kingdom is a rousing, old-fashioned true-life story. A rousing, old-fashioned liberal story too. Set just after the Second World War, it tells the story of how a tribal chief from Bechuanaland (Botswana as is), played by David Oyelowo marries a white English office clerk (that will be Pike) he meets while studying in London in defiance of his father, his tribe and the British government. It's a film about race, racial prejudice, British imperialism and the early days of Apartheid.

Ask Pike what it is, though, and she'll tell you it's first and foremost a romance. It was not the politics but the love story that caught her attention. Because, she says, that's where her head is.

"I want to make more love stories. That's how cinema started really with people making love stories and I don't know we've all got too clever and seemed to shy away from it."

"For me love is always a risk because you're exposing yourself emotionally. I think that's something I believe and I think it's something I find moving because I think it's an act of bravery in some ways. It's easy to not commit and you have to open yourself up obviously and opening yourself up means you can get hurt. So I think it's always courageous and here was a story where the courage was mind-boggling."

This, by the way, is the first thing she says to me in our time together. And, yes, she's talking about the film but she's also talking about herself. She's not only good company but she's open and candid.

Her own love story is, of course, the stuff of tabloid headlines. These days she is bringing up her two children, Solo and Atom, with her partner Robie Uniacke. The tabloids are always eager to remind readers that he's an old Etonian former heroin addict (as I am doing here too, let's face it.) Understandably, that's not how Pike describes him.

"I've met my soul mate who is another outsider really and we both have our own sort of oddities and it's fun, it's really fun."

This is what you might call a happy ending. As recently as 2014 the Daily Mail, in its typically caring and charitable way, described Pike's love life as a "train wreck".

The evidence for this comes from two previous relationships that ended badly. She met her first love actor Simon Woods while they were studying at Oxford University. The relationship ended and Woods went on to marry Burberry's creative director Christopher Bailey. Another relationship with the director Joe Wright got as far as sending out the wedding invitations when Wright called it off.

She's strong enough to look back on these experiences positively. "Someone else asked me about that. They said: 'You've had a rocky love life'. I don't think so. I think it's a really normal kind of love life for someone who has a few important relationships that teach you and they don't all work out. I think an actress who hadn't suffered any heartbreak … Maybe I'd be the same. I think everything goes into your work. I don't see it as a rocky road or anything I see it as a pretty fair-on trajectory to get to the person you're meant to be with.

"I was aware that I got a lot of pity after I didn't get married to Joe Wright. We were really in love, but it wasn't the thing for life. And I've ended up with the right person. It's not like: 'Oh that was the love of my life and I'm never going to get that back.' But it's interesting that's the perception. I suppose because I'm not very interesting they try to make a story.

"There are some lucky people who have never suffered any kind of heartbreak but I need every experience I can get in my job that's for sure, you really do you need it all. You've got to take those emotional risks."

There speaks a romantic. And someone, too, comfortable in her own skin. Success might have something to do with that. Success or motherhood.

She's not so sure. "There are times when I know I'm a competent mother and I've got a good job but sometimes I'm still in a chaotic mess at home and I think: 'When am I going to stop feeling like a student?' Not all the time, but sometimes. I still can't cope with the tax return. 'When is this going to feel like my life is in order?

"But maybe my life is never going to be in order and this is the dysfunction that makes me an actress. Maybe my brain is in disorder, my body is in disorder, and somehow something's made sense of when I play someone else. It sometimes feels like that."

She clearly enjoys the work. Even when she is being directed by notorious perfectionist David Fincher, as she was on Gone Girl, a man who is not averse to a retake or two. Or 50.

"He's completely brutal. He'll come in and say: 'The close up's fine, the midshot's not as good.' He said 'anyone can shoot stuff. It takes balls to reshoot it.' And he will. He just keeps going. He'll reshoot until he gets perfection and that's partly what gives you a sense of the uncanny when you see a film like Gone Girl.

"One of his directions is 'smoother, faster.' And even if it's getting out of a car he wants everything smooth. There are no jerky movements. Even the murder has a kind of beautiful choreography to it. It's almost smooth even though it's violent because it's so rehearsed. Everything works as a fluid movement.

She does the action of cutting a throat as she says this. Smoothly, fluidly.

"He's amazing to work with," she continues. "And then you think: 'How am I going to be able to work with someone else when I don't have 56 takes to get it right in?' And then you realise your own spontaneous instincts are good too. There's a rawness that's also interesting sometimes. Obviously we didn't have 56 takes on this film."

Fincher has said he wanted Pike for the role of Gone Girl's "amazing Amy" because, like the character, she had grown up a single child. Single children, he suggested, "interface with the world differently." True or false, Rosamund?

"True, because you have much more adult understanding. You haven't got a playmate. Your parents are your playmates and therefore you have a more adult view of the world.

"You don't know anything about siblings, which is a crucial thing. It's the one thing I feel I have missed out on and I can never get. Maybe as I watch my own children I'll get to understand it from a kind of inside perspective but in terms of acting it I can never fully own it. All the subtle complications and the rivalry I don't understand."

But you can imagine it surely? That's what actors do. You've never murdered anyone either as far as I know, Rosamund. Unless there's something you haven't told us?

"No. I know. I know. But it's a subtle thing."

Ask her about the texture of childhood and she'll start talking about the smell of damp, and gin and tonic, her mum's Ellenette hair spray, her dad's coffee and the thrilling scent of the dressing room. Her parents were both opera singers. They were gregarious, sociable. Pike was the girl who sat in the corner spying on the adults and their liaisons. "I used to love the fact that people would dismiss me as a child and then talk over me and actually I'd be picking up everything."

Her mum, she says, was a little overprotective. "So I wasn't able to walk places on my own very, wasn't allowed to watch films that were too old for me … as is the law apparently.

"Ironically, I was the person taken home from a birthday party because they were going to watch a Bond film. Which is humiliating at the time but all these things give you your mettle when you're older. I had enough experiences of being the different one. A bit of parental embarrassment is probably quite good for you, isn't it?"

Her notion of herself as an outsider starts here maybe. She learnt the cello but it was always acting that called to her. Because of a love of words, she says. "But funnily enough now I love scenes when I can do it with no words."

Our time is nearly up. Rosamund, I ask her, is life intrinsically tragic or absurd? "Oh, absurd, I think."

What scares you? "Drowning. Empty swimming pools. Sometimes aeroplanes scare me. Sometimes I go through phases where I'm on the plane sleeping and I dream we're crashing. That's horrible. Then periods I'm completely fine.

"But then I'm used to dealing with fear a lot of things scare me and then I do it. Like I went wing walking last year."

Wing-walking? Really? Yes, she tells me, thrilling at the memory. "I do push myself to do things. How high did we go? High enough to experience freefall coming down.

"I was interested in the 1920s and it was the sport women did in the 1920s and I got myself 1920s flying gear: the jodhpurs and the little leather hat. And the jodhpurs were flapping madly up in the sky it was insane but I wonder if I can even show you a picture …"

She gets out her phone and she does just that. Pike standing proudly beside the plane in her Amelia Earhart gear and then up in the sky. Why would you even do that, Rosamund?

"It was like an adrenalin rush. I'm not really an adrenalin junkie but sometimes I push myself in that direction and I seek that. My grandmother had passed away and I was missing her and I don't know … It was pretty amazing. It was the biggest thrill. It is the having done it which is marvellous, because everyone says 'you did that?' and you can say, 'Yes I did!'"

In life Rosamund Pike wants to be able to say, "Yes I did!" That's what she's recognised about herself.

A United Kingdom (12A) is in cinemas now.