When cellphones were pretty new and smartphones were being thought of but not yet invented the conventional wisdom was, “No one is going to carry around a device all day! That’ll never happen!”

And that was what most people believed. It was the obvious thing to claim.

And it was, as it turns out, completely wrong. People in fact do carry around smartphones all day. Something in only a decade or so went from, “Impossible. Will never happen” to “Of course, who doesn’t carry their smartphone everywhere?”

That shows how fast what is obvious can change, and how little-recognized it is when it does. And it always does.