Steve Jobs used to call the computer a bicycle for the mind. Apple's always been best at the pedals and handle bars. YouTube Steve Jobs used to tell a story about how he first became inspired by the idea of what computers could do.

He'd say that once, when he was a kid, he was reading a science magazine and he found an article ranking animals by the efficiency of their movements.

At the top of the list, there were cheetahs and hawks. Way down at the bottom, there were humans — relatively slow on their two legs.

But then Jobs noticed a second list in the magazine.

This one compared humans on bicycles versus all the other animals. Humans were suddenly the most efficient animals on the planet.

Young Steve Jobs realized that was the power of machines, of tools.

Later, Jobs would say that the computer is a "bicycle for the mind" – a tool that speeds us along much faster than we could ever go without it.

If that's that true, then the best parts of Apple's "bicycles for the mind" have always been the handle bars and the pedals.

The handle bars and the pedals are the parts where the human touches the machine, and the machine responds in a joy-inspiring way.

Apple became a $470 billion company over 40 years by examining all the known technologies for how humans can interact with computers, selecting the best technologies, and then perfecting them through a blissful marriage of hardware and software design.

In the 1980s, it was the mouse — invented at PARC and made mainstream by Apple. Paired with graphics-based user-interface, it made home computers plausible.

In the early 2000s, it was the clickwheel. Paired with the iPod's simple software it made carrying a hard drive in your pocket worth doing.

Then, in 2006, came the iPhone with its miraculous touchscreen. It was far better than any consumers had ever experienced at ATMs or kiosks till then. Paired with iOS, it made smartphones accessible to everyone.

Sometime over the next five years, Apple began to go through the same process. It examined the world for technologies humans were using to interact with computers, looking for one it could perfect the way it had the mouse and the touchscreen.

It found one, and on October 4, 2011, it came out.

That was Siri.

Like the mouse, clickwheel, and touchscreen, Siri was supposed to be a new way for a human to move their "bicycle for the mind."

The plan was for the human voice to go through a computer's microphone, and for the computer to react as simply as a bicycle moves when you pedal.

But unlike the mouse, clickwheel, and touchscreen — or bicycle pedals — Siri doesn't work 100% of the time.

In fact, according to a report from Pipar Jaffray's Apple analyst, Gene Munster, it only works about 79% of the time.

That's too rare — by about 21%.

Steven Sinofsky, who led development of the very successful Windows 7, says on his blog that "a general UX principle…is anytime you push some feature on your customer you really want it to be right (correct, useful, helpful) for him/her 100% of the time."

"If not, chances are your customer will recall the negatives of the feature far more than the positives."

Can you imagine how frustrating it would be if the touchscreen only worked 79% of the time? Very few people would have ever bought an iPhone.

The reason it feels like Apple has stopped innovating to so many people is that the last time it tried to do what it does best — perfect a technology that allows humans to interact with computers — it failed. And that was two and a half years ago. The last time it succeeded was 2006 — eight years ago.

(It's impossible not to wonder if, before he died, Steve Jobs thought Siri would be a breakthrough technology the way the touchscreen, the mouse, and the clickwheel were. He died on October 5, the day after it came out. Maybe he thought it would be a huge success, and that's why he told his biographer that Apple had finally cracked TV. Maybe we haven't gotten the Apple TV we've been told to expect years ago because it leaned heavily on Siri, and Siri doesn't really work.)

The good news for Apple shareholders, Apple fans, and humans who like "bicycles for the mind," is that, according to several reports, Apple is about to come out with a new kind of computer built around a new kind of input technology.

That's the iWatch.

According to several reports, the iWatch will have sensors on the back of its face where the watch touches the skin. Supposedly, those sensors will be able to do things like monitor the wearer's blood flow, sugar levels, and more.

According to Thomas Lee and David R. Baker at the San Francisco Chronicle, Apple hired a "renowned audio engineer" named Tomlinson Holman to develop software and hardware that would allow a watch on your wrist to listen to your blood flow and then alert you when "turbulence" indicated that you were about to have a heart attack.

If the iWatch works 21% more often than Siri does, Apple will have done what it's always done to such great success, once again.

For years, companies like Google and Nike and Samsung have been working on wearable technology.

It seems that Apple has been observing their efforts, and is finally ready to come into the market with something more mainstream-friendly — a bicycle for the mind we all want to ride.