The thing about Jennifer Aniston is that even if you're on the other side of the room, there is some immediate connection, some natural warmth. She doesn't power-grin, she smiles broadly. She doesn't just give the requisite attention, she interacts with enthusiasm.
It's easy to understand why she's always been America's sweetheart; behind those cobalt-blue eyes and sun-streaked hair there's a pragmatic businesswoman, smart comedienne and long-standing showbiz trooper.
"I've lived a very charmed life although all those weird things that happen to celebrities do make you question yourself," she mulls. "When I see myself in a magazine, I don't think 'it's me!' – it's just somebody doing a job who's all good and glammed-up."
Aniston is good, but not very glammed up in her new film, Marley and Me, based on the best-selling book of American newspaper columnist John Grogan about his family's relationship with their neurotic dog, Marley.
"I got the book around Christmas 2006 from three different people," says Aniston with her lop-sided grin. "It was a book that everybody loved and I read the back cover and thought: 'It's a book about a dog?!' Okay, I'm a dog person and I have two dogs. I know people think I'm cranky with my unconditional love for my dogs. However, three copies! So I made a little pile and left them. Then I was sent the film's script and thought that something was going on."
She read the script. David Frankel, the director of The Devil Wears Prada was to direct and Owen Wilson was to co-star. Only too soon she found herself with her cheeks covered in meat baby-food and a Labrador called Marley licking her face.
"It's not a dog movie," Aniston's keen to stress. "It's a story of the arc of a marriage. I age from 22 to 40 in the film and I play a mother for the first time. It's about how a couple starts a life together with expectations and dreams and the challenges of a marriage. Least of all with a four-legged fiasco who eats the answering machine and has the telephone for dessert.
"I've heard there were 22 different dogs playing Marley in the film and I almost took home the one who is on the film's poster. They were so adorable."
Aniston should know about the challenges of matrimony. Once half of Hollywood's most glamorous couple, things with then husband Brad Pitt didn't work out when he fell for his co-star in Mr & Mrs Smith, Angelina Jolie, in 2004. Ever gracious about the split, she's clearly sick and tired of being dragged over the divorce facts again and again. To her, these stories seem like they're "a 100 years old" and it seems like she's bent over backwards not to excoriate her ex and to move on.
It's almost undignified to ask this peach of a girl crass personal questions. Yes, she says, she's dating singer John Mayer, nine years her junior, who she met last year at an Oscar party when Sheryl Crow introduced them.
"I barely knew his music and then we ran into each other a week later, and that was that."
And no, she says, she's not pregnant yet, but intends to have children.
"You know, there are so many details that are inappropriate to discuss," she says but not with rancour. "Losing your privacy can be somewhat surreal and the pressure becomes more and more magnified. I'm baffled by it. It's very weird to have people talk about you and read things about yourself that are just not true. But I, like everyone else, buy the mags and read about what's happened to so-and-so and all that stuff."
Aniston is now 40 and seems to be getting hotter.
She's a full-time working girl. Her production company, Echo Films, is developing several projects, and her last film, He's Just Not That Into You, with Ben Affleck, became a hit when it was released in the UK last month.
She also has her charities, which range from orphans in Mexico to cancer, and her friends who can't wait to say nice things about her. Directors love her and co-stars comment how on the ball she is. Once America's favourite Californian cover-girl, she's sort of matured into an icon. At an age most women in Hollywood shrink away from, she looks great.
Clearly her lifestyle of eating well, running, yoga and taking care of herself works.
"That 'thing' of 40 is kind of awesome," she laughs. "I don't feel 40. I'm still pretty immature. I'm saying I'm 30 plus 10 rather than 40.
"I just feel like I'm literally coming into my own – with my body, with myself.
It's fantastic! I'm doing fine, thanks!"