Woody Allen put his finger on the problem, said Gary Hirshberg, co-founder and chairman of Stonyfield Farm, addressing the 400 attendees of Inc.’s third annual Leadership Forum. “He said, ‘I’m not afraid of death. I just don’t want to be there when it happens.’ I think that’s why it’s hard to think about leaving your business, but the day is going to come.”

He was referring to the end of his own journey, which had begun with the founding of Stonyfield in 1983 and concluded with his decision to step down in date January. The key turning point had come in 2001, when he’d engineered a unique merger with his largest competitor, Groupe Danone. Danone agreed to purchase 85 percent of Stonyfield stock over a two year period, while keeping Hirshberg as CEO and letting him retain three of the five seats on Stonyfield’s board, thus giving him operating control.

Over the next decade, Stonyfield continued to grow under Hirshberg’s leadership, eventually reaching more than $370 million in annual sales. Along the way, Stonyfield introduced one innovation after another that revolutionized the industry and set new-;and very high-;standards for businesses seeking to promote environmental stewardship.

And yet it was not his considerable accomplishments that Hirshberg had come to talk about. He mainly wanted to share with the audience the mistakes he’d made and the lessons he’d learned. There were six of them:

1.     Keep clear on what you do and don’t do well and stick with the former.

2.     Have your own personal advisory board that can warn you when you lose focus-;because you yourself won’t see it until it’s too late.

3.     When everything is going great but you suspect you might be missing something, take a two- or three-month sabbatical.

4.     In hiring a successor, it’s best to date before you get married. Remember that you can’t know whether the fit is right without working together, and that you’ll be handing over to the person something extremely dear and precious.

5.     Don’t underestimate the insecurity that results when you leave. Make sure that you give people enough warning, so that they have time to prepare themselves emotionally.

6.     It’s not what you’ve done that counts. It’s what you’re doing. The past is over. You can’t go back and change it. The best way to predict the future is to invent it.