Twiggy was just 16 when she was catapulted to fame, making waves in the Swinging Sixties with her androgynous look, short hair and large eyes.
Half a century on, the 66-year-old looks back on her younger self as almost a different person.
"She never really goes away," she said.
"I always say, she's like my little friend who sits on my shoulder, because wherever I go in the world, there's always a T-shirt with my face on or a handbag with my face on or a keyring with my face on. She's like my little friend really.
"And she didn't do bad for me actually."
The iconic model, whose real name is Lesley Lawson, was discovered after a fashion journalist spotted some photographs of a teenage Twiggy hung in a hair salon.
Twiggy is the daughter of a factory worker and a master carpenter, and was raised in the London suburb of Neasden.
She said: "When I became a model, I was probably the first working-class model. Models in those days came from middle-class and upper-class families, and modelled if they were pretty enough until they met their rich husband.
"So I kind of came out of left field, really. It wasn't a job option then, for somebody working class.
"Whereas that's changed. I think when I was little girl, all little girls wanted to be ballerinas or film stars. I think if you go into schools now they all want to be models. They want to be Kate Moss and Cara (Delevingne) and whoever."
But the model, who went on to a career in fashion, films and the stage, said this career option was now open to people from many backgrounds.
"I think you can come from anywhere now," she said. "If you've got what it is people are looking for, it can happen."
She added: "I think what happened to me happened a lot because I didn't look like anybody else. But you don't want to be the second one, you want to be the new one of something new. I don't think you can plan that.
"Some people are sprinkled with magic dust. We don't know why."
Twiggy has now turned her hand to designing glasses, producing her second Aurora collection for Specsavers - and she will not stand for anyone dictating that certain styles are for women of certain ages.
"It's rubbish," she said. "I was with a woman a couple of weeks ago who was in her eighties, she looked amazing, she was wearing really funky clothes, she had a great pair of glasses on, she had bright red hair and I thought yeah, go girl! It was brilliant.
"Because I get really - I hate it when magazines say, 'You're 20 you've got to wear this.' Who says? 'You're 50, you've got to wear this.'
"Wear what you feel confident in! Because clothes give you confidence and glasses are the same thing."
The new Twiggy for Aurora range is available from May 2016.