There was a time, many years ago, when I used only one computer for my day-to-day work. It was a laptop, and it was with me most of the time, at least during the workday. I accessed my digital information exclusively on this device: email, files, etc. I kept my calendar on a (paper-based) Franklin Planner. For mobile communications, I used a beeper. I told you it was a long time ago — a simpler time.

Then a new device came on the market, the Palm Pilot:

 Image: [Wikimedia](https://en.wikipedia.org/wiki/PalmPilot#/media/File:Palm-IMG_7025.jpg).

Image: Wikimedia.

It was like the paper planner, only digital: it could store your calendar, address book, to-dos, and such. You’d write into it using a gesture alphabet called Graffiti, which you had to learn so you could use the device. But most importantly, you could also sync it with your computer’s calendar, address book, etc. You did this by sitting it on a cradle that came with the device and pushing a button. You connected the cradle to the computer using a serial cable and installed an app on your computer to manage communications between the devices. It was crude and complex, and I loved it. The prospect of having my personal information in digital format with me anywhere was very compelling.

The Pilot was my introduction to the world of syncing information between devices. For the most part, it worked. But sometimes the connection would go awry, mangling data. It wasn’t unusual, for example, to end with duplicated contacts on either end of the transaction. Sometimes calendar entries wouldn’t make it. Cleaning up these messes was a chore. What’s worse, it could mean lacking access to crucial information when you needed it. On the upside, you could tell when the connection had failed. And the occasional mess was a small price to pay: my information wasn’t tied to one artifact anymore, and the Pilot was much easier to carry than either the laptop or the paper-based planner.

My experience with the Pilot marked the beginning of a long quest to find “sync Nirvana” — that is, having all my digital devices synchronize transparently without my having to do anything. After the Pilot I got a series of “feature” phones, mobile phones that included some calendar and address book functionality. At some point, I also started using more than one computer. As with the Pilot, syncing data between these devices was often clunky and error-prone. It worked most of the time, but failed often. Setting up connections between applications often required third-party software and/or unstable hacks. I don’t miss those days.

It’s been several years since I reached “sync Nirvana.” Much of my information ecosystem now resides in “the cloud.” I now have many more “smart” devices than I did in the bad old days: besides my laptop, I now have an iPhone, iPad, Apple Watch, and Apple TV. I can access (and in some cases, modify) my data through all of them, and syncing happens transparently.

Except when it doesn’t. Last week I noticed an appointment on my iPhone hadn’t synced to my laptop. For the first time in many years, I felt a surge of panic. How long has this connection been broken? How many appointments are messed up? Which of the many copies is “The Truth”? After comparing data sets, I discovered that the (third-party) calendar app I use on my Mac had silently stopped connecting to Google Calendar. Something had changed, and sync was no longer working. Was it on Google’s side? On Apple’s side? On the app’s side? I poked around and eventually figured out how to re-set the connection.

This incident snapped me out of my complacency: I’ve gotten to the point where I take effective data synchronization for granted. The fact that it works as well as it does is amazing, given how complex it’s become. Today’s data includes much more than simple calendar and address book entries. This data must sync to several devices, all with different constraints and capabilities. It doesn’t sync over cables but over various wireless networks. It’s a miracle that it works as well as it does. It’s only when it doesn’t — which doesn’t happen frequently — that I notice it’s there, silently and effectively keeping everything in sync in the background.