In Avoiding product management whiplash Hemal Kuntawala describes the constant context-switching that PMs need to do as they move from strategy to execution and back:

Each phase of product development requires a different perspective, almost a different mindset. At one end of the scale you have a big-picture view of the world, like looking at the market you’re in and hypothesising new value propositions. At the other end you have nitty-gritty details like the pixels and font-sizes of your UI.

I like the gentle slopes of the sine wave he uses as illustration, although I think in reality the back-and-forth is a lot less gentle…