We live in the era of the European dynasty but this Leinster team are finding their title defences a difficult second act.
Back-to-back titles were once special events, but since Toulouse won their last Heineken Cup in 2010, Leinster, Toulon and Saracens have won double or triple titles. This year, the Irish province's challenge is to repeat the trick and continue the trend.
Second in their pool with three matches to go, Leo Cullen's men are in decent shape.
Their round two loss to Toulouse has lessened their margin for error, but with the French side due to visit Dublin after Christmas and games against Bath and Wasps teams with no material interest left in the competition to come, they will fancy their chances of emerging as pool leaders with a good seeding.
And yet, there are signs that the all-singing, all dancing champions of 2017/'18 are not quite the force they were a year ago when they won all six pool games en route to their fourth triumph.
They opened with a sensational performance at home to Wasps, but back-to-back away fixtures either side of the November internationals have exposed some previously concealed weaknesses in the armour.
Leinster remain the 7/4 favourites to win the competition, but the market is condensing behind them and they'll be fully aware that Racing 92 and Saracens, who they beat en route to last year's title, appear in excellent shape, while Munster look a more serious threat and Toulouse are on a roll.
A year ago, Sarries were in the midst of losing twice to Clermont Auvergne as they found three in a row too tough to do, but they have drawn breath and come back a better team.
Leinster's issues are partly down to a summer that saw their squad weakened by interprovincial transfers and the retirement of an all-time great.
When Jordi Murphy's transfer to Ulster was confirmed midway through last season, few felt his home province would be negatively affected. Murphy is a quality international, but they're 10 a penny in the Leinster back-row stocks after all.
And yet, the province went into Saturday's game with an unfamiliar back-row as Dan Leavy togged out at No 8 for the first time as a professional.
Jack Conan was only fit enough for a place on the bench, but Caelan Doris and Max Deegan - the next men on the No 8 depth chart - weren't deemed ready for the cauldron.
Murphy started the quarter-final, semi-final and final of last year's tournament at No 8. Leinster were tasked with replacing him from within, but his loss has been felt.
With Robbie Henshaw out of action, Isa Nacewa's presence was missed at the weekend in the physical and leadership stakes.
Joe Tomane was brought in to fill the Aucklander's spot, but he hasn't impressed and is currently out long term, meaning Noel Reid has been deputising at No 12 and while he couldn't be faulted for effort against Bath, he is not the type of player to impose himself physically.
The third departee was Joey Carbery who might have started at full-back in Rob Kearney's place in Toulouse and could have added a much-needed creative spark against Bath.
While the greater good of Irish rugby has been served by his and Murphy's moves, Leinster have been trying to cover from within and it has weakened their defence.
And, while no one will have any sympathy for them given the calibre of player available, it only takes a percentage or two to knock a side off their stride at this level.
On Saturday, Bath's combination of Francois Louw and Sam Underhill created a template for making a great side look distinctly human when they slowed the supply of possession.
A better team than the inconsistent English side would have deservedly won last week's game. Leinster showed great character in digging out a fortunate win, but they have rarely created so little in Stuart Lancaster's time at the club.
With home matches against Bath and Toulouse next before they travel to Wasps for the last game of the competition, there is plenty of scope for them to emerge from this pool in a strong position.
With Henshaw, Seán O'Brien, Jack McGrath, Fergus McFadden and Tomane to come back, they should be stronger by that point - although their position as bulk suppliers to the Ireland set-up does expose them to injury in spring.
A handful of players were part of the squad that won back-to-back titles in 2011 and 2012, but for the majority of this young, talented squad last May was a first European Cup.
They are finding their second act a more difficult task; with teams analysing them to death, rising to the occasion against them and asking them real questions on the pitch.
Bilbao will have sated their initial desire to end a five-season wait for a trophy, the PRO14 double was another feather in the cap; they could be forgiven for having their appetites sated to some extent.
But as the captain of a team that won three titles in four years, coach Cullen knows more than anyone what's required to get back to the summit once again.
A year ago, they launched a comeback win against Exeter Chiefs at the Aviva Stadium that propelled them towards the knockout stages and they'll hope to generate some momentum into Christmas with a win over Bath at the same venue.
In time, the trouble they endured in the pool could be the making of them as they set their sights on their title defence.