When those uninitiated in the longstanding New Year’s Day tradition of running from Mystic to Fishers Island Sound and leaping into the icy water ask, “How can you stand it? Doesn’t it hurt?” we stoic veterans typically reply, “Nah. Don’t feel a thing.”

Truth be told, you do experience a brief, bone-numbing spasm, which quickly gives way to a more savage, throbbing paroxysm of exquisite agony.

Just kidding. The discomfort really is over quite quickly, just like getting a flu shot or hitting your funny bone. Many everyday occurrences are far more excruciating.

The other day, for example, while pounding nails into joists for a new woodshed floor I smashed the hammer down on my thumb, which should show up on Google Images if you searched for a classic illustration of pain.

“My gosh, that certainly hurts!” I exclaimed – or words to that effect.

I also pried up a rotten board with a crowbar only to have the heavy metal tool slip and bash against my knee with enough force that I saw proverbial stars, just like in the cartoons.

Anyway, those incidents were way more unpleasant than diving into 40-degree-or-so water on Jan. 1.

So, here’s the deal: You meet at noon on Thursday on Pearl Street just north of West Main Street in downtown Mystic, and join several hundred other crazy celebrants for a slow run – really, more of a shuffle – to Esker Point Beach in Noank. It’s only about three and a half miles.

Along the way you toot noisemakers, shout greetings to spectators, wave to drivers pulled over to the side of the road and otherwise behave as if you were attending a big, happy party.

When you reach the parking lot on Esker Point Beach Road you start shedding hats, gloves, shirts and sweat pants, since in order to be officially recognized as a New Year’s Day run-swimmer you must dive in wearing only shorts or bathing suits.

By the way, it helps either to carry a towel or have friends meet you at the beach with some dry clothes.

You also must dash back to the sand, shouting and flapping your arms, and then jump in again. Don’t ask why; those are the rules.

Seriously, there are no rules, there is no formal organizers, no competition, no fundraising, no fees and no purpose other than to experience collective exuberance.

Some hard-core runners lope back to Mystic, still dripping, while others hitch rides. For the last few years I’ve taken to dropping my car off at the beach early, running to Mystic by noon and then jogging to the water with the gang.

Loyal readers will recall previous accounts of the event’s origins, so I’ll keep the history short.

Back on Jan. 1, 1969, Amby Burfoot, then of Groton Long Point, who a year earlier had won the

Boston Marathon, Lee Burbank of Mystic and Marty Valentine of Noank all decided to go for a short swim on Jan. 1 They drove to Esker Point, plunged in, got back in their car and drove back home.

The trio did the same thing the next year, but on Jan. 1, 1971 a handful of others joined in and they decided to start off with a five-mile jog from the Pequot Avenue, Mystic home of Johnny Kelley, Amby’s high school cross-country coach. Johnny, who also had won the Boston Marathon and competed twice in the Olympics. They also changed the swimming venue to Groton Long Point’s Main Beach.

Over the decades the number of participants swelled, and people started showing up in costumes.

Two years ago, because of road construction at Groton Long Point, the swim relocated to Esker Point, and last year the start moved to Pearl Street, near the starting/finish line of the Tarzan Brown Road Race.

This year for the first time, participants in the New Year’s Day run-swim (the event doesn’t even have an official name) will pass the new statue of Johnny, my old friend and mentor to generations of runners, who died Aug. 21, 2011.

Like many I’ll be thinking of Kell.

Should auld acquaintance be forgot,

And never brought to mind?

We’ll take a cup o’ kindness yet

For auld lang syne!