An old business mentor gave me some excellent words of wisdom about starting and running a business:
When you start a business, you should have a clear idea of what you want to do and you'll have a vision of the path it will take. That's important. But it's also important to be willing to let all of that go.
Once your business starts running, it will have its own ideas about where it should go and what it should do. And the business knows the right path better than you do. If its trying to go a direction that you didn't have in mind, you're smarter to go with that direction than to try to force the path to the one you had planned.
I think career management is pretty much the same. Your career, after all, is really just a business in disguise. There are too many unknowns -- unknown risks and unknown opportunities -- for you to be able to lay out what your career arc should be in advance. Nimble is the key word here.
But I'm just stating what the article said in different words.