The life of a supermodel looks glamorous—they’re always being photographed jetting off to exotic locales, going to A-list parties and dating rock stars, or movie stars or pro athletes. Plus, they make millions of dollars per year. No wonder so many young girls dream of becoming the next cover girl for Vogue or the Sports Illustrated Swimsuit Issue. Alas, the truth about modeling isn’t as pretty as the magazine covers.

Of all the multitude of girls who aspire to being supermodels, a miniscule number have the qualifications, and few of them will be able to parlay their looks into a lasting career. Unlike most careers, you can’t just go to school and train to become a model—you have to be born with the look.

According to Katie Ford, former CEO of the legendary Ford Agency, “You’re born with the features or you’re not. However, the personality to become a star is something that is really unpredictable, and some people just have that work ethic and the drive and ability to shine in front of the camera, and some don’t.” Here are a few ways to tell if you’re one of the very few who have a chance at making it.

Start out in your teens.
All the famous supermodels were discovered before they were 18. Brooklyn Decker was discovered walking through a shopping mall as a teenager, then moved to NYC at 18. Marisa Miller was first discovered by two Italian modeling agents as she walked through a San Francisco café at age sixteen. A few months later, she was on a plane to Italy to begin her modeling career.

Bar Refaeli got her start in a baby commercial at eight months, and was doing fashion work by the time she was 15. Milla Jovovich began modeling at 11 and was featured by Richard Avedon in Revlon’s “Most Unforgettable Women in the World” ads. At 12, Milla dropped out of seventh grade to pursue modeling full time.

Why so young? Agencies want models they can launch early so they’ll have longer, more lucrative careers. Since most models are over at 30, they have only so many good earning years. Maybe parents don’t want their little girls to enter this world so soon, but the bitter truth is, a model starts young or she doesn’t start at all. Thinking you can graduate from college at 22 and get into modeling is like thinking you can become a pro football player at the same age without playing your whole life up until then.