KIM ZMESKAL CANT WAIT TO GET home each day to watch Days of Our Lives. She's crazy about New Kids on the Block and just loves Arsenio Hall. She seems like a perfectly normal teenager—until you see her room. It's neat. No, it's beyond neat. "I was putting up some pictures," says Kim, "and my mom said, 'Why don't you just stick them up and see how they look?' " But that wouldn't do for Kim. "I measured them out," she says. "I want everything to be perfect."

There's at least one other difference between Kim and her peers—and that also involves getting things right: At 15, she's the best female gymnast on the planet. Last month at the World Gymnastics Championships in Indianapolis, Kim combined painstaking perfectionism with explosive athletic skills to win the women's all-around title. No American woman—Kim's idol, Mary Lou Retton, included—had ever finished higher than seventh at the World Championships.

Zmeskal, the oldest of three children, began training with gymnast kingpin Bela Karolyi at age 6. Since her parents both work—Clarice, her mother, is employed as a contract analyst at Mobil, and David, her father, is manager of a welding-products store—she went every where with her baby-sitter, whose daughter was a gymnast. "I used to have to go up [to Karolyi's gym] and watch," says Kim. "So I decided to try it."

Nowadays, Kim works out six hours a day, which doesn't leave much time for friends or school (she now studies by correspondence) eleven for basking in her new status as an Olympic gold-medal hopeful in Barcelona next summer. "It's weird," she says. "When people say I'm world champion, it doesn't seem possible." She pauses, then giggles. "But I guess I am."