MK

Her messy hair, giant sunglasses and wardrobe full of decaying designer threads have influenced everyone from John Galliano to the girls at the mall. But lately Mary-Kate Olsen has had more on her mind than whether she can wear leggings with heels. There's the responsibility of her $1 billion company, the paparazzi who shadow her every move and the fresh heartache over a tabloid-worthy breakup. Now she's leaving college and her twin sister, Ashley, behind—at least for the semester—and making a fresh start in L.A. Her goals? Get healthy, learn to put herself first and find work as "just an actress" for a change.

Sipping a Diet Coke in a private room at New York's Soho House, Mary-Kate Olsen, the Full House star-turned-junior tycoon, is fiddling with one of her many Balenciaga motorcycle bags. With its dangling leather lariats, signature woven handles and distressed bronze buckles, the bag is as essential to her famously derelicte style as her giant sunglasses and knee-skimming thrift store?chic sweaters. The version she's carrying today was originally mint green, but it's so dingy, covered with stains, pen marks and even a chewed-up piece of gum, that it looks almost gray.

"It explains my life," Olsen says, sighing, when asked about her beloved accessory's sorry state. Pressed to elaborate, the 19-year-old is quick to say that she was "just messing," that she simply meant she has a tendency to wear things out. But Olsen might in fact be on to something. The beat-up bag is an apt metaphor for her current condition: an oft-imitated emblem of chic that over the past year and a half has been dealt its fair share of bumps and bruises.

In May 2004 New York Minute, a big-screen teen comic caper in which Olsen starred opposite her sister, Ashley, fizzled at the box office. The following month, Mary-Kate checked in for a six-week stay at a treatment center for an eating disorder. June also brought Olsen's 18th birthday and her ascension to the position of copresident, along with Ashley (who declined to comment for this article), of Dualstar Entertainment Group. The billion-dollar multimedia company oversees the production of their videos and movies as well as Mary-Kate and Ashley books, dolls, furniture, rugs, clothing and cosmetics.

As her tumultuous summer was coming to a close, it looked, for a while at least, like Olsen would get to enjoy a more typical rite of passage: starting college. But when she matriculated at New York University's Gallatin School of Individualized Study in August, she was met with overwhelming media coverage of her every move—apartment jockeying, nights out at Butter and regular jaunts to the Union Square Starbucks. Then, this past fall, just as Mary-Kate was settling into Manhattan life and her sophomore year, Paris Hilton started dating Stavros Niarchos III, the Greek shipping heir and Olsen's boyfriend of five months. That, it seems, was the straw that broke the camel's back. In October, MK, as her friends call her, took a leave of absence from NYU and moved back to Los Angeles to pursue her acting career.