I have always worn a watch. Ever since I was 13 years old. Back in 1952, an inexpensive wristwatch was accurate to about five minutes a day. But there were no other time sources, except the clock by the bank, or the chime on the radio, so having the time on my wrist was a revelation. Maybe it was my OCD, but it was something I needed to know. Like a compass orienting me in the fourth dimension.

Over the last 70 years, I've worn all sorts of watches. The first big improvement was a watch with a stopwatch function. Now I could take fourth dimensional measurements. Being able to time how long something takes is very important to me, so most of my future watches included some sort of a stopwatch function.

When the 1970s brought the first electronic watches, I wore one. Cheap prices, astounding accuracy, and you don't have to wind them. (Oh, and most had a stopwatch function.) Whenever the latest Casio Databank watch came out, I bought one. You had to enter the data with a tiny keyboard. Some versions had a calculator function, also with a tiny keyboard.

The Timex Ironman Data Link USB was my first "smart" watch. You put stuff together on your computer and then sent it to the watch. No more tiny keyboard. Third-party applications could be added to increase functionality. I had my address book, a bunch of information for traveling, and two stopwatches. The display was always on, and the battery lasted two years.

Which brings us to the current version of the smartwatch -- it's linked to a smartphone and has its own operating system. Like the phone it's linked to, the watch has to be charged at least once a day. But think of the synergy -- a wearable that teams up with your phone to do all sorts of incredible things

Sounds great, but what went wrong? Everyone has a smartphone, but only a tiny percentage have a matching watch. Why didn't today's smartwatches live up to their promise?

The simplest, and also the most visible thing, is the physical design of the watch. At first, all smartwatches -- both Android and Apple -- had rectangular screens. Then, in 2014, Motorola introduced the Moto 360, the first round-screen smartwatch. And everyone said, "Wow! It looks just like a real watch!" And it did, sort of. The rest of the Android smartwatch makers followed suit. Soon after, every Android smartwatch was round.

The new Android software market wasn't for smartwatch apps. Nope, it was watchfaces. Literally hundreds of thousands of them. As long as you have a round smartwatch, might as well dress it up to make it look even more like a real watch. For about 20 seconds until the screen turns blank.

But there are real-world problems in designing and building round smartwatches. It's an engineering challenge to fit the individual piece-parts into a round case. It's hard to make round LCD screens. And it's really hard to write software that does something useful on a round screen.

That's why smartphones, laptops, and tablets are built rectangular. You can see why switching to a round screen helped kill the Android smartwatch.

Notice that Apple didn't fall for this nonsense. Their smartwatches still have rectangular screens, and they sell them by the millions. But their watches have other problems.

Stay tuned for the next episode, where we dig deeper into the world of smartwatches.