For instance, most forward-thinkers could see the post-PC movement coming in some capacity.
But if you asked an analyst in the late 1990s or early 2000s which company would likely lead that movement, there was no reason to believe that it wouldn't be Microsoft. Things can radically change in very short amounts of time.
Still, there are a few things that should've been easy to see.
Of course, people prefer the convenience of shopping for things from home (or anywhere else) to going out to the mall. Of course people like carrying all of their books on one device.
Yet, some very smart people still managed to get things that we see as totally obvious completely wrong.
Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.