When Sonia Sotomayor was a law student, she told a professor that her career goal was to be a federal judge. But more than a decade later, when she was urged to apply for an opening on the district court in New York, her mentor and law partner at the time, David Botwinik, could not get her to complete the necessary paperwork.

“I told him it was a useless enterprise, they would never pick me,” she recalled in a speech at Hofstra University. “He took away my work, put an application on my desk, and said, ‘Fill it out.’”

That’s what mentors do. They’re counselors and cheerleaders, disciplinarians and therapists. They know that some proteges need a kick in the rear, some need a pat on the back, and many need both.

Sotomayor’s story embodies many virtues: from the devotion of her single mother to her own courage as a pioneering Hispanic woman. But one important theme deserves more attention – the critical role that mentors have played in her rise to prominence. Without Botwinik’s persistent prodding, Sotomayor would not be where she is today, a nominee for the Supreme Court.

Justice Department statistics show that youngsters receiving guidance from a mentor are far less likely to start drugs, skip school or lie to their parents. But that’s the big picture. The real joy of mentoring is making a difference and leaving a mark, one young person at a time.