Long before I got my fancy degree to build residential structures and office parks, I made a name for myself in a different trade. I spent seven long, hard years up to my elbows in some of the filthiest—and yes, bloodiest—brown paper sacks you'd ever want to see. It taught me a lot of hard lessons, some I'm grateful for, some best left unmentioned. But I won't ever forget them. Grocery bagging, like all the other dirty little jobs society requires but pretends don't exist, is easy to get into. Getting out is something else. It's like embedded shrapnel. Like a phantom limb.

I first strapped on the apron at a little eight-aisle place in downtown Tempe—a dusty hell of a city where the damned stalked the aisles. But just because it's a godforsaken sandpit doesn't mean its cans aren't placed on the bottom and cartons of eggs on top. And for the next few years, that was my life.

It was a quick-and-dirty intro to this shadowy and disreputable world. And I saw it all: From shabby little shame-filled deals in shabby little smoke-filled break-rooms over who would "take care" of the old lady with four bags full of new groceries and a colostomy bag full of old ones, to the late-night wet-work cleaning up the mess my less-meticulous comrades left behind, to the last-minute drop-off in the trunk of a blonde housewife's sedan before she takes off into the wind. It's a world most suspect but few see—and fewer own up to.

I was one of those few.

But not the proud. That's a different uniform altogether—one with honor and tradition, not one hidden in plain sight. Friend, odds are you wouldn't have lasted three shifts in my world. I wasn't even sure I would myself. It comes at you like a blur in training: This is a pallet-jack, mind your extremities; this is my brown paper bag, there are many like it, but this one is mine, with its own intricate calculus of weights and stresses which must become second nature if you hope to fill it in under 25 seconds; and this slim, simple, sinister tool is your box cutter. Today, everyone thinks they know what that means. Believe me, they don't. Not really.

And it pulls you in. Whether you like it or not, that adrenaline starts flowing the instant the PA system switches on with a hollow electric click like a thin glass rod snapping. Before the cashier even has time to call for carry-out, you're off that milk crate you were standing on (it's best not to ask about the milk crate), walking briskly, unconsciously, toward the registers. Next thing you know, two brown bags are on the counter in front of you, your catch-hand thrust against the far side of the bag, your dominant hand tossing canned goods and packaged meat off the crook of your elbow and into the catch-hand, which arranges it all in a complex, compact, orderly matrix that belies the chaotic shadow world in which you, the bag boy, operate.

It had to end for me—I always knew I wasn't a lifer—and I left under a cloud, though it wasn't as acrid as the cigarette haze in the break-room. Guy named Macon was running things that day, that hot, humid day. Macon found me in the meat-freezer trying to cool off with a Coke, said the place stank like a slaughterhouse. Anyway, I couldn't explain the Coke, not without a receipt, and with only a month left until the first day of school, I decided to walk away.

All those people are ghosts now. You say you'll stay in touch, but you never do. Bagging was the only thing you had in common, and bagging was the one thing you could never discuss. It was a job that needed doing, and we did it, and now it's over.

But there are times, Sundays mostly, when I take the car down to the ValuSave in the town where I live—you don't need to know which town—and when I hit the checkout, I'm there all over again. The greasy tread of the conveyor belt, the beep of the scanner, the rustle of the register detail tape, and, most haunting of all, the sharp crack of brown-bag paper, all make me realize I'll never be truly free of it. Never.

And, God help me, I don't want to be.