The iPhone did not spring fully formed into the world in 2007 from a stroke of genius.

Many on the core development team of the iPhone had worked at General Magic in the 1990's.

At General Magic they'd explored a lot of futuristic personal mobile assistance technologies, but the company failed to successfully productionize it because the tech was premature.

But the exploration and discovery they still accumulated as knowhow; they could feel the shape of the problem space (and, importantly, the dead ends to avoid) in their bones.

Many years later, the technology had caught up, and the ideas they'd been simmering on for more than a decade finally hit the real world situation that could activate them.

The right spark ignited the latent knowhow they had accumulated.