“Truth has nothing to do with words. Truth can be likened to the bright moon in the sky. Words, in this case, can be likened to a finger. The finger can point to the moon’s location. However, the finger is not the moon. To look at the moon, it is necessary to gaze beyond the finger, right?” — Hui Neng, 6th Patriarch of Ch’an Buddhism

A few weeks ago I had a disconcerting experience. It was a beautiful Saturday, and I decided to go for a run. I strapped my iPhone 6s to my arm, put on my headphones and headed out. I had a great run. Later that morning, my family and I decided to go out to lunch. When we were ready to leave the house, I noticed my phone was turned off. “That’s odd,” I thought, “I don’t remember turning it off. Perhaps it’s out of battery for some reason.” I plugged it in to charge, and nothing happened. That’s when I noticed a bit of condensation forming inside the camera lens. Later, the Genius at the Apple Store confirmed my suspicion: sweat from my arm must have seeped into the phone, ruining it. My iPhone was done for, and the repair was more expensive than it was worth. I decided to upgrade to the most recent model.

When I got home, I started setting up the new phone and discovered I didn’t have a backup of my old one. (I thought I’d turned on iCloud backup; obviously I hadn’t.) This meant I’d be setting up the new phone “from scratch.” Not a big deal, I thought, since most of the content on the phone — my email, contacts, notes, photos, music, etc. — all live in the cloud anyways. All except one: my Apple Watch activity history.

I’d been using the Apple Watch since it came out and had been measuring my fitness activity from day one. (Fitness was one of my primary reasons for buying the Watch.) I’d accumulated data — including a stack of “achievements” — for two years, and now it was all gone. I’d be starting over, as though I was completely new to the Watch. I was dismayed. I knew this was “just data” — but still felt a real sense of loss. That I had to go through all of the Watch’s onboarding processes (even though I was by now very familiar with all of it) only added insult to the injury.

After a while, it hit me: health data are not what I really care about with the Watch. What I care about is my health. The data are just a way to measure progress as I get healthier; they have little inherent value for me beyond that. All those closed rings, all those achievements I’d unlocked — they were a mirage. The real achievement was having a body that was healthier than it had been two years ago.

In obsessing over the data, I’d fallen victim to a cognitive bias psychologists call surrogation: when the variables you’re measuring become a higher priority than the thing they’re supposed to measure. It’s not uncommon, for example, for managers focus obsessively on improving measures such as net promoter scores. This is good, as long as everyone is clear that the score has no inherent value in itself; what matters is that customers are actually satisfied. As Peter Drucker said, you can’t manage what you don’t measure… So we look for ways to measure the things we want to manage. Scores are just a way of keeping track — an inherently incomplete way.

We obsess because measurable values can be tied to incentives. For example, I’ve gone on diets to lose weight. It’s not unusual for me to promise myself a reward when the bathroom scale showed a particular number. This creates an incentive for me to reach that number. But all of it — the number, the goal, the incentive — is an abstract construct in service to the real goal: to be healthier. The number on the scale is one of many variables that can be used to track health; I just happen to focus on it because I can measure it.

The loss I experienced when I had to restart my activity tracking was a sign that I’d been focusing on the wrong thing. These numbers and digital medals have little or no value on their own; they’re only useful insofar as they allow me to identify tendencies. What initially felt like a minor catastrophe now seems a blessing: I was forced to come to grips with the fact that, entranced by my new abilities to see information, I’d lost sight of the real goal.