The iPhone, for example, was a spectacular leap forward on the surface. But it was really the product of incremental progress in lots of different areas, ranging from batteries to chip miniaturization, storage, touch screens, carrier negotiations, software, and more.
In fact, Apple was so quick to combine the advances in all these areas into something revolutionary, Blackberry executives couldn't believe it was real. And even once they came to terms with the fact that it really did work as advertised, they didn't see it as a threat to their business.
This is one of the reasons why sometimes it's so important to start things before you feel ready.
The rest of the world may not know it's ready either.