Like many people I mourned the news of Steve Jobs’ death with tears in my eyes, and that feeling in your chest that arrives only when the world becomes a little less.

Less magical. In this particular case.

Millions of words will be written about Steve Jobs in the coming weeks. Appropriate consideration for a man who sits alongside Franklin, Edison and Ford when measuring his impact on the world.

To say that he understood us better than we do ourselves is only the slightest hyperbole.

To point out that he imagined not only possibilities but the ways to make them come true is to recognize the man’s true genius. For without the capacity to make the complex simple, and to then do so by the millions, he would have been a man on a stage in a black turtleneck talking to an empty room.

It is no accident that for the last several years Apple has been recognized as having the best supply chain in the world. “Amateurs talk about strategy. Professionals talk about logistics.” And in hiring Tim Cook to build the world’s best supply chain, Steve Jobs proved he was not only a visionary. But a professional.

Of all the things I have thought and read and heard so far about Steve Jobs, however, one thing stands out to me as the foundation to Apple’s success.

In 1997, on his return to the company he had founded, he met with a group of developers and began to explain how he was going to re-design Apple.

For too long, he explained, Apple had been less than the sum of its parts. And rather than trying to make Apple be more, he was first going to make it be less.

He was going to force Apple to focus. To decide where it was going. To decide how it was going to be great.

And to focus, Apple was going to have to say ‘no’. A lot. To everything that didn’t bring it closer to being the company he envisioned.

This was part of his creed. To simplify. To focus. And to relentlessly say no. "Because only then can you concentrate on the things that are really important."

Of all the many lessons we will be studying for years to come, this is the one that rings most deeply to me.

Whether you call it your Purpose or your Mission or your “Why”, no business succeeds without knowing what it intends to be.

It is a journey that begins not with a yes. But with a great many ‘no's’.

And ends when you have changed the world.