Mary-Kate and Ashley Olsen run a successful fashion line, the Row, but turns out they've been wearing designer clothes for as long as they can remember.

As child stars on "Full House," their wardrobe was composed of adult designer pieces, including from Chanel and Marc Jacobs, cut to fit children.

"We were designing clothes for ourselves as we were so petite," Mary-Kate told The Edit magazine. "So I think that is when we became obsessed with fit, and now the obsession has become a profession."

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According to Ashley, fashion played an integral role in their early lives, as wardrobe fittings were time-consuming.

"We'd be in six-hour fittings three times a week," she said. "We had to wear 12 different outfits!"

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However, the 27-year-olds are now happily living life away from the cameras - and out of the paparazzi glare, when possible.

"There is a threshold in New York, and once you pass that and are considered a New Yorker, they leave you alone," Ashley said. "But we're at the office every day, then home or out for dinner, so there aren't the opportunities for them to take pictures. For the most part you try and avoid it. … [I do], at least."