I have been breathing, more or less constantly, for almost exactly half a century now, but respiratory prowess aside I can’t seem to think of this pending milestone as especially meaningful.

It’s merely a number, 50.

A round number, to be sure, as well as an interval of 10, a category we seem especially fond of to delineate the passage of time.

But as memorable birthdays go, my 50th, which arrives on Sept. 22, doesn’t seem any more noteworthy than, say, the 26th or the 38th.

This of course is a common experience.

I expect that for most of us the first dozen or so birthdays feel particularly momentous, if only because we haven’t had a great many of them, which affords us a fresh perspective.

(Also I think we appreciate the presents more, since most of us, as children, lack the means to procure much of what we believe we need. Although, even as I recall thinking that my early birthdays were events of some significance, I couldn’t tell you now which gifts I got when I turned seven, or 11.)

I also imagine — and dearly hope I will be able to investigate this matter for myself — that once you’ve made it to 90 or so, each subsequent birthday bears a special sheen by dint of its statistical rarity.

But the greater number of these annual events in between, it seems to me, pass without any great fanfare.

You go to work, if it’s a work day. You eat cake, but I happen to believe that should be a regular event rather than one reserved for special occasions.

Still and all, as I approached another birthday that would temporarily have my age ending in a zero, I had occasion to compare the impending day to some of its predecessors.

And I quickly realized that my memories of three birthdays, none of which was a decennial, were quite a lot more vivid than for my 30th or 40th.

The first of these was my 16th.

As was common then, but is less so now, I had convinced myself that my entire existence depended on acquiring my driver’s license on that very day.

To have to wait even 24 hours would have been cataclysmic, a blow to my fragile psyche which would never heal.

(My capacity for dramatic exaggerations was well-honed, a common ability, I’ve noticed, among teenagers.)

My birthday, fortunately, fell on a weekday.

I passed the driving exam somewhere between “with flying colors” and “barely scraped by,” managed for the DMV camera a smile that wasn’t at all contrived, tucked my license into my bi-fold wallet (vinyl, Velcro closure, very much a relic of 1986) and drove the couple of miles to my house in Stayton.

Then I made the sort of stupid decision that, if not the sole province of 16-year-old boys, surely is the sort for which they have an Olympian proficiency.

I agreed to go driving around with a friend.

This would have been unwise even under the most common definition of the term — indeed, it wouldn’t even be legal under today’s more stringent restrictions on teen drivers.

(Restrictions which I think are legitimate, a position I would have disagreed with, and vehemently, as a 16-year-old.)

But I’m not talking about picking up a friend to show him my license and display my driving skills.

I mean we drove around in separate cars.

And if there’s any prospect more distressing to consider than one teenage boy driving, it’s two.

We made it pretty close to a mile before the crash, though, so it’s not as if we were completely hapless.

What happened is that I was in front and I decided, in the spur-of-the-moment way for which 16-year-olds excel, to whip into the parking lot at our high school.

I performed this maneuver with far less alacrity than was necessary, considering my buddy was following at a distance more typical of a NASCAR race than a suburban street.

I still remember the sudden jolt and the sickening crunch of bending metal and the certainty that I would never again drive a vehicle that had my dad’s name on the registration.

No one was hurt, so I can chuckle at this inauspicious start to my tenure as a licensed driver.

(Albeit a rueful chuckle; even after such a considerable span of time I can feel the shame, like the flush of red spreading across my cheeks.)

I was also allowed to drive again in a surprisingly short time.

Two years later I turned 18 on the first week of classes for my freshman year at the University of Oregon.

I remember that birthday exquisitely because my parents, who lived about 60 miles away, drove down to Eugene and brought me a cake.

I suppose this ought to have embarrassed me. But I don’t remember feeling anything but grateful at having such a normal thing happen during a period that was a much more dramatic milestone than turning 50. Adding another digit is nothing compared with becoming an adult, or at least a reasonable facsimile of one.

Another three years passed.

Again I have a distinct memory of the day I turned 21, which was at the start of my senior year at the U of O.

I was living in an apartment in Springfield and on my way home from classes I stopped at a market near campus and bought a bottle of Henry Weinhard’s beer.

A single bottle.

I remember the purchase vividly — most particularly I remember my hesitation, prompted by the fear that the clerk would confiscate the brew even though it was a mathematical certainty that the purchase was legal.

But what I can’t recall, at this late date, is why I bought one bottle rather than the more customary six-pack.

I’d like to think that I chose the lone bottle because I recognized this as a more poignant way to honor a milestone — the lager version of the ceremonial bottle of champagne.

More likely I was prompted by simple penury.

Quite a lot has happened in the brewing industry in the ensuing 29 years, the grocery coolers teeming with all manner of craft ales.

But I might toast the half-century mark with another bottle of Henry’s. It’s no longer brewed in Portland, but I’d like to think it is a true Oregonian.

As I am.

Jayson Jacoby is editor of the Baker City Herald.