MEMPHIS, Tennessee—The sun drops low over the Mississippi River, settling like a golden coin into an earthen pouch.

The sight reminds me of distant days and vanished opportunities.

This river—the great river—has beguiled me for nearly half a century. When I was a young man, still lean of limb and life experience, I passed two memorable years as a graduate student at Saint Louis University.

I chose that school, in large part. because of its proximity to the Mississippi.

My boyhood I spent in Ohio and Indiana. We did little traveling—mostly to see relatives on my mother’s side of the family in southern Indiana.

Occasionally, though, we would go to visit my cousins in Minnesota, the children of my father’s older brother. Their house was set back on a bluff with a distant view of the river. I remember standing on their small front lawn, looking down at the Mississippi and marveling in a child’s way that it stretched all the way down the country, almost like a watery spine.

I knew. even then. that I wanted to see as much of the world as my life would allow. A river that snaked all the way from the headwaters of the north country down to New Orleans and beyond was more than an enticement. It was an enchantment.

When I arrived in St. Louis, I was a young man on a motorcycle. I used those two wheels to open new windows.

On weekends, I rolled over roads north and south of the city, hugging the banks of the Mississippi, soaking in the reality that I was in a new and, to me, magic place. During the work week, I often would ride from campus to Laclede’s Landing, rumbling over the cobblestones to park my bike and just sit by the river, where I’d either read or just watch the water flow by.

I’d read Mark Twain, of course. I’d also devoured Jonathan Raban’s superb “Old Glory,” a travel book written by a Brit who himself was obsessed with Twain and the Mississippi.

As the end of my first year of grad school approached, I was at loose ends. I needed to find a job over the summer months.

A buddy provided an option. His uncle was an executive with a company that ran barges up and down the Mississippi. They hired young men over the summer season.

The job, my friend explained, didn’t require much other than a strong back and a tolerance for solitude. Laborers worked 30 days on and 30 off, never leaving the barge when they were on. The crew members worked, slept and ate in shifts.

The pay was good, my pal said, but it didn’t work for anyone who couldn’t stand his own company.

I was hooked. The thought of traveling up and down the Mississippi, seeing the river from that rare vantage point, was irresistible. I was young, not much north of 21, and fit, so the notion of working hard as something other than thinking was appealing, too.

I told my buddy to tell his uncle that I’d love a spot if he had one for me.

Then an editor for whom I’d worked the previous summer—a man who became a mentor for me—called to ask if I’d come back to work for him again over June, July and August.

It was, in professional terms, not even a close contest. I knew I wanted to be a writer, someone who made his living weaving thoughts and observations into seamless packets of words.

If that was the career—the life—I wanted, I couldn’t say no, no matter how much I wanted to see the Mississippi from a boatman’s perch.

I asked my friend to thank his uncle, but that I wouldn’t be available after all. I spent the summer writing.

It was the right choice for many, many reasons.

But I would be lying if I said that the sight of the Mississippi still doesn’t make me wistful—still doesn’t conjure up visions of living and laboring on a barge for a month straight.

Now, looking at the sun drop low over the Arkansas bank of the great river, I find myself thinking that even the most fortunate lives and the right choices still have room within them for regret.

They linger, even as the Mississippi rolls on.