I work in a warehouse where my rate is on a screen and I want to describe what that does to a person over four years.

The job is picking. An item on a shelf, into a tote, scan, next. The target where I am is a hundred and eighty-four units an hour. There's a handheld that tells you your current rate, and it updates constantly, and there's a number on it that is green or amber or red.

Four years I've watched that number more than I've watched anything else in my life.

Things I know about myself from the number that I never knew before: I'm slower on Mondays by about six percent. My rate drops after I drink water, so I drink less water. I'm fastest between hour two and hour four, and after hour nine I'm basically falling.

If I'm forty units behind at lunch I can't make it up, so a bad morning decides the day before noon.

I'm forty-seven. I have a bad left shoulder from this and a doctor's note in a drawer that I've never handed in, because handing it in means a conversation about whether I can do the job.

What nobody outside understands is that there's no villain. My supervisor is a decent kid of twenty-six who has his own screen with his own number on it, and his number is made of my number. The whole building is numbers made of numbers. There's nobody to be angry at, which is why everybody's just tired instead.

The part I'm actually confessing:

I've become someone who resents slow people. Not at work — everywhere. In the grocery line, on the sidewalk, my own mother on the phone. Something in me has been trained for four years to treat another person's pace as a thing taking from me, and it does not switch off when I badge out.

My wife said it first, in February. She said, "You sigh at me." And I said no I don't, and then I paid attention for a week, and I do. I sigh at my wife when she's telling me about her day, because she takes too long to get to the point.

Four years ago I was a patient person. I'm pretty sure that's true and not nostalgia.

I can't leave right now — the pay with the shift differential is better than anything else I can get at forty-seven with my back, and we've got two in school.

So the question I actually need answered is: has anyone come out of a metrics job and gotten themselves back? Not "found a better job" — I mean, did the sighing stop? How long? Is there something you did on purpose, or does it just fade? Because I'm more worried about what I'm turning into than about my shoulder.