The woman who helped define Sheryl Sandberg’s career reveals the key to making it to the top

In her 2013 book "Lean In," Sheryl Sandberg describes her career as less of a ladder and more of a jungle gym.

A "jungle gym scramble," she writes, better accounts for the many detours, barriers and, indeed, joys she experienced on her way to become Facebook's chief operating officer.

It's a metaphor she borrowed from prominent journalist Pattie Sellers — to whom she gives credit in the book — and one which many of us can relate to.

Sellers understands careers. She learnt from the routes taken by some of the world's most preeminent powers, from Warren Buffett to Melinda Gates, as Fortune magazine's former assistant managing editor.