It has not been particularly difficult for Liverpool to avoid breaking the golden rule this century: to never fall in love with a loan player.
The romantic dalliance with Nicolas Anelka is looked back upon fondly but tinged with regret, while flings with Aly Cissokho and Victor Moses only shine through rose-tinted glasses when compared with liaisons as disastrous as Arthur Melo.
But Ronald Araujo feels different. He tidies up after himself. He cares about his appearance. He can cook and clean. He respects his mother.
And he is helping rehabilitate a vaguely lost, identity-less Liverpool more effectively than anyone permanently wedded to Anfield.
With the hosts having endured a demoralising, morale-sapping half-hour, featuring a customary Marcos Llorente away goal in their traditional Champions League meeting with a Madrid side, one simple action from Araujo helped shift the momentum and mood.
As an Atletico attack disintegrated to the extent the ball was played all the way back to Jan Oblak, the decision from Araujo to relentlessly chauffeur it into the opposition penalty area was fundamentally impractical. Liverpool’s press and structure had been a shambles to that point, and their right-back leading a one-man, 50-yard, headless chase was inherently counterintuitive.
Yet the passable Andy Robertson impression set a tone his team-mates strived to match thereafter, and energised a fanbase which had simply settled for being made to feel something.
Liverpool equalised minutes later and went on to win relatively convincingly.
There might be no more accurate and concise summary of Andoni Iraola’s nascent Reds than in the first two goals of this game.
One scored at either end for a start: Liverpool being sliced open straight through the middle in the first instance, then pressing their way to a well-worked, clinical response.
Atletico’s opener was predictable in its preventable dreadfulness. Liverpool’s midfield crumbled in the face of a single Julian Alvarez feint, and the defence held a flimsy line which neither caught Llorente offside nor stopped him having a clear run at goal.
Araujo was implicated, but shared only a fraction of the responsibility in comparison to Dominik Szoboszlai and Milos Kerkez.
But the Hungarian pair atoned for those mistakes. It was Kerkez’s press on Lee Kang-In which won possession in an unsettled Atletico’s half, and Szoboszlai’s calm finish which eventually brought Liverpool’s equaliser.
An exquisite backheel flick assist from Araujo only added to his already burgeoning cult heroism with the supporters.
The impact of that goal on Liverpool was stark. They immediately looked more confident, more assured of the plan. The individuals came together as a team, as if reminded by the noise that facing a Diego Simeone side might be a little easier when working in tandem.
Florian Wirtz sparkled. Rio Ngumoha looked bright. Szoboszlai impressed. Bradley Barcola was electric and ought to have scored; Alexis Mac Allister took care of that soon after with a thunderous strike, meaning the midfield which dissolved yet again in defence flourished in attack.
That volatile imbalance makes Liverpool difficult to measure in these early phases under Iraola, but one constant is helping them through.
While these issues are old remnants of the Slot era, Araujo is their rejuvenating them as something new, borrowed and blaugrana. They might as well accept the inevitable and activate that £47m buy option now.