It happened five years ago, but it could have been yesterday, or never, or even tomorrow.

My husband and I were on the way back from somewhere — church maybe, improv rehearsal, brunch — it doesn’t matter. We stopped at our neighborhood Starbucks so I could get a mocha (grande, nonfat, no whip, extra shot), and a bag of beans (Verona, ground for espresso, but destined to be brewed in a Krupps automatic drip machine).

The pattern of this visit was similar to most others: I bantered with my barista, who commented on the color of my hair that week, asked how my writing was going, mentioned she’d bought tickets to my improv troupe’s show the next week. I spent a few minutes people-watching (a father and his teen daughter were both absorbed with their cell phones, two teens were on a very awkward first date, a table of young women was engaged in animated conversation), and then, drink in hand, I made my way to the door.

A man was entering just as I was leaving, and we ran into each other in the way that usually only happens in sitcoms, though my coffee never tumbled to the ground, and the well-used leather-bound notebook he was carrying remained firmly in his grasp.

I looked up to apologize, as he looked down to do the same, and our eyes met.

Suddenly, everything was still. Sound no longer existed. The real world had faded to nothingness.

What I saw, instead, was a future from a parallel universe.

I saw myself meeting this man, and asking his name. Saw us sharing a table, half-empty cappuccino mugs pushed aside as he shared with me the travel adventures in his journal, and I showed him the novel I was trying to write.

I heard the strains of his acoustic guitar (gentle, folky), with percussion provided by the thumping tail of a golden retriever. I smelled his cologne (faintly aquatic, with a hint of rum) as he leaned close to help me re-string the cello I hadn’t touched in years.

I knew, somehow, that the shark tooth that hung from the leather thong around his neck was no mere affectation, but was worn with real meaning, and I knew he’d understand that the jade prayer beads encircling my wrist meant a great deal to me, even though I’m not actually Buddhist.

I saw us having an extended affair, meeting in foreign countries, sharing art, and music, and incredible stories.

I opened my mouth to speak, or maybe to kiss him.

And then — somewhere behind me — a cell phone rang, and my heartbeat was echoing in my ears. Time had begun flowing once more.

I heard my voice apologizing to him, but it was as if it belonged to someone else: “I’m so sorry,” I said. “I hope I didn’t splash you.”

“No,” he answered, in an accent that I would not recognize as Portuguese until I heard it again from a character in a movie, days later. “The fault was mine. I was not looking. Permit me…?”

We brushed by each other, he moving toward the counter, me stepping out to the sidewalk. I waited for the door to be fully closed before I crossed the parking lot to my husband in our idling car.

“Sorry for taking so long,” I said.

“It wasn’t that long,” he answered.

“Seemed like forever,” I muttered, mostly to myself.

I looked at my husband — really looked at him, in the way people who have been married for decades don’t often do — my goofy, sweet, loyal, low-key husband, whose adventures are limited to virtual worlds, and who thinks the greatest drink ever is warm orange soda.

I felt guilty, as if I’d somehow cheated on him during a split-second encounter with a stranger. As if I’d actually done something wrong. As if a quantum relationship experienced in a coffee bar doorway was a threat to what I had with him.

I shook my head, and reached across the center console to touch his khaki-clad leg. “I love you,” I told him.

He drove us back to our too-big-for-just-us suburban home, the one we’d hoped to fill with children, but ended up filling with books and dogs instead. We greeted the animals, and I left my coffee on the dresser in our bedroom. “I think I’d like a nap,” I said. “Join me?”

Hours later, I woke to a dark house, a snoring husband, and my forgotten mocha that had gone completely cold. I grabbed my notebook from my nightstand and sat in the bathroom trying to recapture, on paper, what I’d experienced in the Starbucks doorway.

It could have been yesterday, or even tomorrow. But it was really five years ago, and right now, and never. I ran into a man, and received a gift: a quantum fluctuation in the universe granted me glimpse at someone else’s (mine, but not me) reality, fading like an echo, and tasting of coffee.

I never ran into him again. Most of the time, I’m glad about that.

Sometimes, though, I wonder.