Years ago, back in the days when you had to feed the television with farthings to keep it working - actually I may be misremembering this. Half-crowns? Florins?
Anyway, back in those days there was a nice gag on a TV advert for Hamlet cigars. It featured a young sculptor lovingly fashioning a fully-membered Venus De Milo.
We cut to the artist admiring his work, and noticing a tiny flaw at the back of the marble beauty's right arm.
Two tentative taps, hammer on chisel. A third - and the arm falls clean away. The artist shuts his eyes, stricken. Cut again, to the now chisel-free sculptor lighting up a consolatory cigar. And cue the voiceover: "Happiness is a cigar called Hamlet…"
If only. If only he had let it be. Known when to finish.
In sport, as in art, the final flourish can be the unhappy ending.
The image doing the rounds this week was of a young Frenchman with, frankly, too much time on his hands at the end of a cross-country race.
Jimmy Gressier was a runaway winner of Sunday's (December 9) men's under-23 race at the European Cross Country Championships on a mudlark of a rainswept course at Tilburg in The Netherlands. Having grabbed a tricolore in each hand, he had a Good Idea. Why not cross the line with a bit of a flourish, sliding on the knees, footballer-style?
The reason why not soon became apparent. This was not primped and pampered Premier League turf. This was old school, an intractable pig of a course. So instead of sliding, Gressier came to a sudden halt and - arms encumbered with patriotic emblems - tipped up and planted his face into the finishing tape.
It could have been worse. At least he won. Which was more than could be said for Lindsey Jacobellis when she had a Good Idea as she approached the finish line five seconds clear of the pack in the first Olympic snowboard cross final at the 2006 Turin Games.
On the penultimate jump, by way of adding a finishing flourish to her impending victory, she went for a trick. And misjudged it, hitting the deck and allowing Switzerland's Tanja Frieden to move past her for gold.
Oh calamity. And of course, it being the nature of these things, she never subsequently won an Olympic title despite securing five world titles.
Who knows? Perhaps it is now standard for elite athletes to be reminded that concentration is never more necessary than at the apparent point of victory.
It was a truth that memorably eluded Scottish 800 metres runner Tom McKean at the 1991 World Championships as he led virtually all the way in his first round heat before having a Good Idea and slowing down, letting two men beat him to the two qualifying places on the line.
McKean took it all in good heart.
"The race is 801 metres, not 796," he said. "That lesson sank in pretty quick. But I've got to try and treat it as history. You can't live on it otherwise you'd go daft in this game."
Actually the race is 800m, but he was very close. And it was, and always is, those four forgotten, abandoned, taken-for-granted metres that are so often, actually and metaphorically, the heart of the problem for the imminent winner/scorer.
Jacobellis was a high profile over-reacher within US sport. But there are legions of others who have snatched defeat from the jaws of victory down the years…
For Gressier, read Leon Lett.
In January 1993, during Super Bowl XXVII, Lett, playing for the Dallas Cowboys, intercepted the ball after mishandling from a Buffalo Bills opponent and set off on a 60-yard run to the end zone. At the ten yard line he slowed and held the ball out in his right hand by way of celebration. Good Idea? Not so much, as the Bills' fastest player, Don Beebe, managed to cover back and bash the ball out of the spaced Cowboy's grasp before he crossed the line.
"He has not marked touchdown!" roared the US commentator. "It was knocked out of his hands and went out of bounds in the end zone which would give it to Buffalo at the 20. And look at Lett! If they call that a no touchdown he's going to dig a hole and craaaawwlll out of this place from there."
"He's going to need a big hole," said the co-commentator.
"He celebrated too soon…" said commentator one, before the announcement was made: "The play has been ruled as a fumble in the field of play." No score.
Thankfully, from Lett's point of view, the Cowboys still romped home by 52-17. So it fell into the sub-Jacobellis category in terms of faux pas, although statisticians do still like to point out that Lett's lapse cost his team the highest points score of any team in Super Bowl history.
Even so, Lett would surely have been joshed, rather than harangued, by his mates in the dressing room.
And the same would surely have been the case for the French goalkeeper and captain in this year's FIFA World Cup final, Hugo Lloris. Like a lot of goalkeepers, Lloris seems to have a frustrated outfield player inside him, and has established a reputation down the years as a kind of keeper-cum-sweeper.
On this paramount occasion the predominant voice in his head was that of sweeper rather than keeper as he decided, in the 69th minute of a World Cup Final, that it would be a Good Idea to smartly dribble past the oncoming Croatia forward, Mario Mandzukic. It did not work, and Mandzukic was able to dispossess him before rolling the ball over the line.
France were already 4-1 up, however, and ran out 4-2 winners. Otherwise - quel dommage.
And while we're on the subject of French sportsmen, remember Jean van de Velde at the 1999 Open Championship golf tournament?
The enduring image is of him alongside the 18th green, minus socks and shoes and with trousers rolled up, shin-deep in the waters of the Barry Burn, in company with his ball. The stuff of nightmares – but it was reality for a player who had arrived at the 72nd hole with a three-shot lead.
Despite that, Van de Velde had had a Good Idea. Use the driver from the tee! That did not go well. But he still had shots to spare. Then he had another Good Idea. Do not play safe and then hit the green with your next shot, go for broke!
His shot drifted right, ricocheted backwards off the railings of the grandstands by the side of the green, landed on top of the stone wall of the Barry Burn and then bounced 50 yards backwards.
On his third shot, Van de Velde's club got tangled in the rough on his downswing, and his ball flew into the Burn. After taking his bemused paddle, Van de Velde decided to take a drop ball, and then bunkered his fifth shot. He got out to within six feet of the hole, and made his putt for a triple-bogey seven, which allowed Justin Leonard of the United States and Paul Lawrie of Scotland to draw level.
The Scot won the following day’s three-way play-off.
If only. But in truth sport would be the poorer for the lack of bad Good Ideas.