And yes, as the attached photo attests, both the stubble and scalp now boast more salt than pepper.
But it's not just the hair. At 40, everything hurts.
On Saturday I had a few old schoolmates over for a game of golf and a few ales to celebrate the four-decade milestone.
Some time in the evening, somewhere amid the liquored din I caught a line from old crooner Leonard Cohen, whose ballad Tower of Song was playing in the background: "I ache in the places where I used to play".
It was a melancholy but honest and rather fitting lyric for my 40th. I was tired. We'd just finished nine holes of golf - nine holes of what 20 years ago I would have deemed a leisurely pace.
Back then I would have laughed at the "exercise", because back then I competed nationally in athletics, and to boot could bench press 130kg.
But I struggled. We apparently moved so slow that a half-witted group following behind peppered us with golf balls. It was their way of telling us we weren't moving at the preferred pace.
A few terse words were exchanged on the final hole. Their spokesperson, an angry evolutionary cul-de-sac, told us we weren't being courteous; which, he told us, was why for the past five holes they'd fired balls in our direction.
For a heated 30 seconds, golf almost became a contact sport.
It was tempting to celebrate my 40th by dealing with the situation Happy Gilmore style. To deal with morons you sometimes need to speak their language.
A straight right to the mouth of the group's alpha male would have been a great way to remember the milestone.
But I'd like to think that, unlike this mob, I've managed after 40 years to control the Neanderthal within.
I was 40 all right. I'd not only slowed down, but mellowed.
But the weekend event wasn't about me lamenting the passing of time. I'd prefer to be thankful for where I am and what I've got. Thankful, too, that I'm here at all.
One mate yesterday inquired as to the "most stupid" decision of my life.
There've been many. But in hindsight it was during my late teens with a group of friends in Hastings where, a little worse for wear after spending the evening in the pub, we jumped the Frimley Aquatic Centre's fence for a free dip somewhere around midnight.
Stripped down to undergarments, I climbed the high-diving platform, inched my way to the edge and dived headfirst into the black abyss.
Dropping at terminal velocity it suddenly dawned that I hadn't checked to see if there was any water in the pool. Maybe they drained it at night? I braced for a head-first impact with concrete.
Given I'm writing this, there was, mercifully, water in the pool. Things almost literally fell into place for Darwin that night.
It was but one of many funny but near-tragic anecdotes I raised with a friend on Saturday, including the time as a 7-year-old my brother shot me in the knee with a .22 bullet; or perhaps the time a friend and I came across a beehive on a fallen branch. Vaguely recalling something I'd seen my father do, I tipped litres of petrol on the hive, then without retreating a step, threw a match. Both of us lost eyebrows. The tip of my nose blistered. I told mum it was sunburn.
I mention these events not because I consider myself a survivor; not at all.
I raise them in an effort to cheer myself up - given it's highly possible I've now lived more than half my life.
Despite trying to stay positive, I keep coming back to the poem Nothing Gold can Stay, in which poet Robert Frost seems to be trying to tell me to accept my old age:
Nature's first green is gold,
Her hardest hue to hold.
Her early leafs a flower;
But only so an hour.
Then leaf subsides to leaf.
So Eden sank to grief,
So dawn goes down to day.
Nothing gold can stay.
Anyway, I'm off to the gym to work on bettering my former bench-press record - and prove Mr Frost a liar.
Mark Story is assistant editor at Hawke's Bay Today.
