When Pep Guardiola capped his first season as a manager at senior level with an historic treble at Barcelona he might have wondered how he was ever going to better that success. He'd climbed Everest while still a managerial novice.
He's had to wait a decade, but the answer may materialise over the final couple of months of his third season as Manchester City manager. He's scaling improbable heights once again.
Guardiola has enjoyed plenty of success since that Nou Camp treble, winning two more La Liga titles, another Copa del Rey and another Champions League, before three successive Bundesliga titles with Bayern Munich, twice adding the DFB Pokal to that haul.
But he's never matched that treble. That could all change over the next two months. Thanks to the Carabao Cup a quadruple is on offer for City this season, with the first trophy in the bag.
The Premier League title remains in their own hands, although Liverpool are making them work for the defence of their crown, the FA Cup draw has opened up with a semi-final against Brighton on the horizon, while Tottenham are the opponents in the Champions League quarter-finals.
It would be an unprecedented achievement if City can walk off with all four trophies. If Guardiola thought he may never repeat the high of Barcelona's treble, then this would be a season he would find almost impossible to follow.
In 2008/09 Barcelona returned from the March international break with 16 games to play. If City are to go all the way this season they will have a further 15 games to play in this campaign.
The comparisons between the two seasons aren't an exact science. Ten years ago Barcelona went into the international break having already secured their place in the Copa del Rey final and while they had 10 La Liga games left to play - City have eight Premier League games remaining - they were in a more commanding position.
Barca had a six-point lead over Real Madrid at that stage of the season, while City are actually two points behind Liverpool, who have only seven league fixtures left to play.
The good news for anyone looking to draw a comparison between how Barcelona coped with the pressure of finishing that season off and how City will fare over the next nine weeks (as long as they make it to the Champions League final in Madrid) is that not only did Guardiola's side get over the line in every competition, but they did so in style.
Treble winners will always go down in history, but it was the final 16 games of that season that really defined that Barcelona side. It was the cavalier way they swept all before them in April and May that made neutrals fall in love with them.
They'd already enjoyed some virtuoso performances - on nine occasions before the March international break they'd scored five goals or more - but it's games in the final weeks of the season that we remember.
In the second game after the last international break they tore Bayern Munich apart in the Nou Camp in the Champions League quarter-final first leg. A 4-0 half-time advantage ended the tie as a contest.
A 4-0 home win over Sevilla in La Liga followed, before a Champions League semi-final first leg draw with Chelsea in Catalunya. Before the return a week later, Barcelona - still with that six-point lead and with five games remaining - went to the Bernabeu and bested their fierce rivals 6-2. It was an astonishing win on Madrid turf, an evisceration of their nearest challengers that all but guaranteed the league title.
Four days later Andres Iniesta's last-minute away goal at Stamford Bridge sent Barcelona to the Champions League final.
With the league title secure as Real imploded, Guardiola's side eased up in La Liga, but they won the Copa del Rey in style, beating Athletic Bilbao 4-1 at the Mestalla to confirm their domestic dominance.
In Rome they conquered Europe as well. A Champions League final with Manchester United looked to be an even fixture on paper, but Barcelona were utterly dominant. Goals from Samuel Eto'o and Lionel Messi proved Barcelona were the gladiators of the continent, and they'd won the treble with statement performances against their nearest rivals.
Right now City would probably take falling over the line in the Premier League, Champions League and FA Cup. But a decade ago Guardiola saved the best for last with his Barcelona side. If he can repeat the trick history is within reach for the Blues.