Every innovation that changed the world started out with people asking: Why would I ever need this?

When the Wright Brothers built the first airplane, few were impressed. Same with the steam engine, the car, penicillin, the computer, the Internet, and the laser. Everything is obvious in hindsight, but what becomes life-changing usually looks ridiculous at first glance.

Take the telephone, invented in the 1870s. It seems crazy that anyone could look at an early telephone and not instantly see it as groundbreaking and useful. But that's exactly what happened.

In his excellent book At Home, Bill Bryson wrote:

When Alexander Graham Bell invented the telephone in 1876, no one anywhere, Bell included, saw its full potential. Many didn't see any potential for it at all. Executives from Western Union famously dismissed the phone as "an electrical toy." ... All Bell did really was put together existing technologies. The components necessary to make telephones had existed for thirty years, and the principles were understood.

This is common with inventions. Most inventors are impassioned tinkerers. Rarely do they have a map outlining exactly what they're after, especially in the early years. Thomas Edison was "so smitten with the idea of progress that he invented things without having any idea whether or not those things would be of any use," Bryson writes. "Nobody was better (or worse, depending on how you choose to view it) at inventing things that had no obvious need or purpose." Building is done by trial and error. Breakthroughs come serendipitously and in ugly, rickety stages. That's almost how it has to happen when there's no instruction manual for what you're doing.

The result is a lot of early inventions look like toys, because in the early stages that's exactly what they are. It leaves them prone to ridicule by those lacking the imagination to see past the toy stage.

Even when an invention is refined and starts to look like something useful, its power is rarely appreciated. Here's how the early telephone was received, according to Bryson:

Displayed at the Centennial Exhibition in Philadelphia in the summer of 1876, [the telephone] attracted little attention. Most visitors were far more impressed by an electric pen ... Phones were originally seen as providing services — weather reports, stock market news, fire alarms, musical entertainment, even lullabies to soothe restless babies. Nobody saw them as being used primarily for gossip, social intercourse, or keeping in touch with friends and family. The idea that you would chat by phone to someone you saw regularly anyway would have struck most people as absurd.

This is another underappreciated phase of progress. People today can't comprehend how anyone lived without cars, air conditioning, or computers. But those who lived without these things were pretty happy with their lives. You don't miss what you can't imagine. So breakthroughs are met with more ridicule, especially by older generations. Why would I need a car if I already have a horse? Why would I need a phone when I can already send a letter? Why would I need email when I already have a phone? These questions sound bizarre in hindsight, but they're asked every time a life-changing invention is unveiled.

To me, a fascinating question is: What are people ridiculing today that will totally change the world tomorrow? What amazing innovation sounds so ridiculous that no one is even talking about it, walking right past it at the equivalent of the Centennial Exhibition?

There's no easy answer, almost by definition. I asked some friends. They said self-driving cars, wearables, and green energy. But these innovations have already won. Few people are actually laughing at them. The fact that they instantly sprung to mind shows the technologies are already accepted.

A lot of people look at new, exciting technologies and wonder how they'll change the future. It's fun, and normal. But the history of innovation shows it's more complicated than that. Some of the biggest future breakthroughs look absurd and useless today.

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Contact Morgan Housel at mhousel@fool.com. The Motley Fool has a disclosure policy.