When Lloyd Blankfein was preparing to retire as chairman and CEO of Goldman Sachs on October 1, 2018, he wrote a poignant letter to employees that captured his ambivalence about stepping down. “It’s always been hard for me to imagine leaving,” wrote Blankfein, who had just turned 64. “When times are tougher, you can’t leave. And when times are better, you don’t want to leave. Today, I don’t want to retire from Goldman Sachs, but…it feels like the right time.”

A version of this article appeared in the November–December 2019 issue of Harvard Business Review.