Dustin Hoffman is in playful mood in his new film, playing a 200-year-old toy shop owner. Alison Jones hears how he found the child within.

Dustin Hoffman is no stranger to the make-up chair. In Little Big Man, he was aged from 17 to 121 (Hoffman was in his early 30s at the time). In Tootsie, he donned fake boobs, hair and eyelashes to play an out-of-work actor posing as an actress.

For his latest film, Mr Magorium's Wonder Emporium, he has reined in the face make-up, however, preferring to illustrate the fact his character claims he is 243 years old solely through a Don King hairdo and Denis Healey eyebrows.

"I remember Little Big Man - it took about six hours. I think it was the first time prosthetics were used. Dick Smith was the genius make-up man of his time," says Dustin. "The first thing the director for Magorium (Zach Helm, who is also the writer) and I both agreed on was we didn't want prosthetics.

"If we were to do it realistically, it's a zombie movie - what are you going to do, exhume this guy?

"What we hit on was, if I could believe that he believes he is 243, then I've solved it. That meant he had to have a certain amount of eccentricity. The child in him was more important than the literal age. Can we retain that part of ourselves for our entire life?"

"Also," muses the two-time Oscar winner who turned 70 this year. "You reach a point where you say, I want to be me in my third act."

Such quirky personalities usually find themselves in charge of chocolate factories (see W Wonka) or toy shops, which is the case with Mr Magorium.

He has decided that, having run out of his lifetime supply of Italian shoes, the time has come to turn up his toes and hand over the store to his assistant, played by Natalie Portman.

Dustin has, of course, adopted a man-child persona before for his Academy Award-winning portrayal of the autistic-savant Raymond Babbitt in Rain Man.

That said, Magorium, for all his strange tics, is far more at ease in the company of others than Raymond. The key to the character was tapping into the innocence and imagination we usually lose at about the time we stop believing in Santa Claus and the Tooth Fairy.

"What the movie wants to be about is the idea that the child in us has diminished as we get older. That's the most pure part of ourselves, the most unadulterated. It's the individual that never existed before, and presumably will never exist again," says Dustin, his insight gained by the experience of having raised six children and being a grandfather to two more.

"At a certain point, that starts to have diminishing returns. The oddball (label) is then placed upon him, defines him and in school he doesn't fit in - and so we start to lose him.

"We let go of that most invaluable part, because we want to fit in. And the more you fit in, the more you are generic. So the child in us is the intrinsic desire to not let that be taken away.

"I knew a painter years ago, a very good abstract painter. He came in the house and saw the painting that my 36-year-old daughter, Jenna - then three or four - had done on the wall.

"He said in passing 'I can't do that any more. I wish I could do that'. And I knew what he was talking about."

Oddball is a label that could easily be applied to Dustin himself. At just 5ft six and three quarters tall, he is on the short side for a leading man.

He had a nerdish, fumbling intensity as a young man that gave way to a dishevelled charm in Kramer Vs Kramer and All The President's Men, but he has never been movie star handsome. Which is precisely why he beat out his President's co-star, Robert Redford, for the lead in The Graduate, because director Mike Nichols thought no one would believe that the athletic, beach-blonde California would ever have problems with women.

"I was lucky enough to become a movie star, by a freak accident," admits Dustin, who reportedly only took up acting because he was failing all his other college courses.

"After The Graduate, I get this crap load of scripts. So suddenly I'm able to cherry pick the best of the worst. As you get older, the volume of scripts diminishes, because the leads are written for guys in their 20s."

A method actor from the Lee Strasberg school, he was a contemporary of Robert Duvall and Gene Hackman, and roomed with both as a young man in New York, at one point sleeping on the latter's kitchen floor.

Dustin's true skill lay in his versatility as a character actor, which he ably demonstrated in his next hit, Midnight Cowboy.

The tubercular, limping, conman Ratso Rizzo was a world away from the well-laundered, if sexually compromised, Benjamin Braddock. Further acclaim followed for the controversial Straw Dogs, Papillon, Lenny, Straight Times and Marathon Man, although Dustin has had his share of misses. Ishtar, in which he co starred with Warren Beatty, was a particular low.

He has coupled his big screen character roles with some quality stage work and regrets he hasn't had the opportunity to do more.

"I did Merchant of Venice here (England) for almost a year, and my kids all moved here and had British accents after three weeks, which appalled me. I thought they'd never lose it," says Dustin. "I'm surprised that so many years have passed since I've been back on the stage, but it all comes down to what you want to do more.

"There's a piece I've been working on for about four or five years and I think I'm finally going to be able to act and direct it."

Five years past pensionable age, in the UK at least, and having been a star for nearly 40 years, it's unlikely Dustin needs to work.

Now he takes part simply because a role tickles his fancy or there is someone he particularly wants to work with.

"At my age, you become the support." he smiles. "But there are some good parts there. I just pick what I think will be fun to work on. I liked

Marc Forster very much. "I took a supporting part in Finding Neverland (which Foster directed) because I like Johnny Depp's acting, and I got to do two or three scenes with him.

"Then Marc was doing Stranger than Fiction, and called me up, and asked me if I wanted to do it. That's how I got to know Zach Helm, who wrote that."

Once shooting Mr Magorium, Dustin found his attempts to regress were aided by props that rang a bell deep in the recesses of his childhood memories.

"I just have a vivid memory of having a spinning top. I didn't understand how it could work and make a sound," says Dustin.

"It's interesting that they still exist today and we had them on the set.  Because they were made of metal and it was during the Second World War, we were asked to go down to the corner and give them to the war effort. There was a big stack at the gas station - all the kids had come down and given their toys. I think my spin top turned the corner, and that's why we won."