For thousands, perhaps hundreds of thousands of years, change occurred so slowly that it was imperceptible. Neolithic man had no idea that his Old Stone Age ancestors lived lives fundamentally different from his. Iron Age Greeks were dimly aware that a preliterate Bronze Age preceded them, neither steel nor writing is mentioned anywhere in Homer.

For most of our history, humans lived the same lives their fathers and grandfathers before them, and they expected their children and granchildren would live the same way they did. Oh sure, they were aware of natural disasters, wars, of different kings and dynasties, and other events, but even if they might be aware that the Old Ones, the Anasazi, lived differently, evidence of that prior age was only preserved in myth and legend. No one actually remembered what it was like in the past. Renaisssance art depicts New Testament events and characters in contemporary dress and late medieval armor, and even today, our religious films portray Jesus' disciples dressed like 19th century Arabs.

It hasn't been until fairly recently that people have been aware that their grandparents wore different clothes, used different tools and techniques, perhaps even spoke a different dialect of their language than they did. 15th century Columbus would have been amazed by the complexity of a clipper ship from four centuries later, but he could have learned the rigging eventually. But nothing would have prepared him for a steamship.

A man born at the turn of the twentieth century knew his grandfather was aware of railroads, telegraphs and repeating rifles, but had never heard of internal combustion, aircraft, or electric lights. Women didn't show their ankles until after the Great War, and their mothers scolded them. Today, a sabbatical or hiatus in your career can leave you incapable of catching up where you left off when you return to the workplace.

The pace of change increases, not just technological, but cultural as well. We have not yet reached a point where the culture simply cannot change any faster because people will no longer be able to keep up with it. But that event, (similar, but not quite the same as Kurzweil's Singularity) will itself be a change with profound consequences. Even though people may be incapable of adapting any faster, our economy, technology and culture have become addicted to ever faster rates of change. Something has to give.

Even now, people are starting to say ¡No más!