Belief still there insists Nacewa
Isa Nacewa's two years away from Leinster gave him two things. First, it rebuilt a love to play the game for the only club to which he would countenance a comeback.
Second, it gave him perspective for when he did return.
He has had the separation of distance and time with which to measure how Leinster's standards were when he left compared to how they are now.
"I genuinely believe they're probably higher than when I left," he said.
The assertion comes as just as big a shock as the way Wasps wiped the floor of The RDS with Leinster on Sunday.
The former Auckland Blues mental skills coach has been able to get his head around that statement when so many others would be puzzled, even disbelieving of it. He has reasoned it thus.
"It was disappointing that we got caught off guard physically at The RDS," he said.
"Every Leinster team prides itself in dominating at The RDS and we just didn't.
"Then, when Wasps got scoreboard pressure on us, and we tried to chase the game, our compounding errors didn't let us get back into it.
"A few uncharacteristic mistakes from guys across the whole team just impacted on how we got to chase the game and we just couldn't get back in."
Leo Cullen's description of Leinster as "disjointed" has irritated some; been dismissed by others as just an excuse.
The bulk of Leinster's squad formed the majority of the Ireland World Cup brigade.
They had been living in and out of each others' pockets for the best part of four months.
This comes with a complication.
"It is hands-down two different environments, two different game-plans.
"Every player is different," he said.
"They have all come back in different head spaces - guys that did play and guys that didn't play.
Back at Leinster, there was a heavy price paid.
"We had 15 starters against Treviso and 15 new starters against Scarlets and then had to merge them both for the Wasps game.
"If that's the word he used. That's probably the best way to describe it."
The normally understated coach has a fiery side to him and it erupted after Sunday.
"Leo had some good harsh words for the group," revealed Nacewa.
"We addressed it as a group because that's what we are and rightly so.
"It was the right message for the time."
Leinster have to go from zero to four (or even five) points in six days in what has to be an accelerated improvement or they will be sprawled out on The Champions Cup scrapheap.
"We can't look any more forward than this week," he warned.
"It is a must-win game. There's no other 'if' or 'but' about it.
"We've got to go to Bath and we've got to step up and do the job."
Leinster will need every body they can muster from the casualty ward.
Nacewa is confident he will be one of them.