My initial experience of that familiar sensation occurred back in 1982, soon after the mass-participation event had taken its grip upon the nation's collective imagination.
It was a sunny March morning, and I was out running near my home. I had reached that satisfactory stage where the sweat was on me and the legs were moving without complaint.
An elderly runner approached. He was wearing one of those aerated shirts which resemble the section on a grater for nutmeg or carrot; and he had across his forehead a broad red sweatband.
As we drew closer I noted two further details. He was doing a funny, breathing-type thing - all rhythmic and deliberate. And he was travelling faster than I was.
Upping my pace, I prepared to exchange the traditional greeting of those who meet in such circumstances - a nod of the head, maybe a clipped "Morning."
So when he enquired: "Doing the London?" I was, as it were, caught on the wrong foot. I realised immediately what my response should be - a comradely "Yep!" Or even better: "Afraid so. Westminster Bridge or bust!"
The actual response - "No" - possibly lacked a little in wit. But it had an effect.
My inquisitor said nothing derogatory. As he passed, however, he seemed to be carrying himself with just a touch more conviction, moving just a shade more easily.
I, in contrast, felt the earth tugging me down. I began to be aware of a pain in my side. I began to wonder if the section of the path I had reached was actually uphill, in real terms, even though it did not appear so. Could such a thing be possible? If all the surrounding topography, by some freak of nature, conspired to create that effect?
Or was it simply that I was feeling inferior?
Somewhere in that sudden deflation, guilt was playing its part. Similar emotions troubled me a couple of years later when a colleague was preparing to run the event.
Dave Bedford, Britain's jack-the-lad world 10,000 metres record holder in the 1970s, once said the hardest part of his training was getting out of the front door.
I always thought Bedford was making life unnecessarily difficult for himself on this count. If the front door was such a problem, why not simply use the back door instead?
But no such weakness afflicted my friend, who was unwavering in his dedication to running 26 miles, 385 yards.
By the time the rest of us had sloped off to the canteen on our break, he would already be pounding his way along the Embankment, or Blackfriars Bridge, or however far it was he managed to get during the one-hour break, breathing in the fresh night air, at one with himself, working towards a goal.
With his gaunt cheeks and serious Mars bar habit - this was a man making maximum use of his time and ability. And as we sat and stuffed our faces, we all felt... guilty.
Marathon guilt, though, occurs in its purest form on the race route itself. And the best place to observe it is the roadside pub.
The killer stretch of the London event comes at mile 16, when the 30- odd thousand strivers negotiate the long, windswept loop around the Isle of Dogs.
There is naught for comfort here other than the occasional brass band and the ragged cheers of those who dot the route.
Often, you see runners reel exhaustedly from the proceedings here. Perhaps they are simply stunned by the realisation that, as the Marathon race literature points out, Canary Wharf has 4.4 million square feet of office space and is constructed with 10 different types of Italian marble.
But these individual dramas only serve to heighten the uneasy feelings which nag at those who gather on the pub forecourts clutching drinks and fags, ostensibly to cheer the gallant foot soldiers onwards.
The problem with runners is this: they make everyone else, by definition, a non-runner.
All those who stand and watch, whether they like it or not, are mutely challenged by what they witness. They tip their ash, and stare into their glasses, and mutter their traditional speaking parts: "Keep it going!" "Cheers!" "Hup-two! Hup-two!" "You're all mad!"
And the real giveaway: "I could do that." O drinkers at the Ambivalent Arms, nursing your beer and your regrets... But what has all this to do with the New Year? Very simple. Every year, without fail, I resolve to run the next London Marathon. Cheers.Reuse content