The history of great sporting occasions is littered with what-ifs and what might-have-beens.
But in the quiet moments ahead of Saturday's World Cup semi-final against France, Wales coach Warren Gatland may ponder the misfortune that has ended up favouring his team's increasingly potent challenge for the Webb Ellis Cup.
When veteran fly-half Stephen Jones limped out of the warm-up ahead of Wales' opening pre-tournament match against England, there was a hasty reshuffle that could have thrown preparations off-balance even before they began.
Jones' Scarlets team-mate Rhys Priestland, a likely utility player at the World Cup, was switched from full-back, where he had trained all week, to number 10 just five minutes before kick-off.
It was his full debut, having appeared off the bench once during the Six Nations as a late replacement in the win over Scotland, and again during an end-of-season game against the Barbarians elevated to full Test status.
Gatland has since admitted the withdrawal of 102-cap veteran Jones gave Priestland an opportunity he was otherwise unlikely to have received ahead of the tournament.
But he seized his chance with such alacrity that it was he rather than James Hook, with Jones still unavailable, who was chosen to start Wales' World Cup campaign in the pivotal role.
The 24-year-old has since confessed that far from being the "cool, calm" player who impressed Gatland, he was actually "in a bit of a panic about remembering the calls" when he first got his chance against England.
"That day the players around me, especially Mike Phillips and Jamie Roberts, helped me," Priestland recalled.
"It was probably five or six minutes before kick-off [that I was told I would be playing at fly-half].
"All summer the coaches asked me to run at full-back because they said at the World Cup you need players who can play in more than one position.
"I have always thought I was a 10. I never really thought I was a full-back, but I learnt last year and the year before that you can't say no to any position. I was just happy to play.
"It is still a bit surreal to turn up here and see all these [media] microphones. I don't know what to make of it."
That was before injury struck. The shoulder problem that forced Priestland off late on after steering Wales to victory in their quarter-final against Ireland has cost him his place for Saturday's semi-final with France.
But the blow of this latest piece of injury misfortune is softened by the fact that Hook - possibly Wales' most talented back - was waiting in the wings to reclaim a starting place, with the experienced Jones providing cover from the bench.
Hook, who started Wales' first two matches at full-back, suffered a shoulder injury himself against Samoa, but that too had an upside. Leigh Halfpenny came off the bench and his match-turning contribution saw Shane Williams score the winning try.
Even Wales' a bitterly disappointing 17-16 defeat by the now-departed Springboks in their World Cup opener had a silver lining, keeping Wales in the opposite side of the draw to Australia and New Zealand, who are now sizing each other up in Sunday's other semi-final.
As well as turning these potential setbacks to their advantage, Wales have also made their own luck as the tournament has progressed.
No matter the personnel, a team full of new-found heroes insist on saying: "We have won nothing yet."
But they are wrong. Wherever they now finish, this Welsh team have won the hearts and minds of the neutrals following events in New Zealand, as well as reaffirming a nation's pride in their efforts.