Are we witnesses to the most thrilling comeback stories ever? Or simply the best, and the worst, manifestations of player power?
"We saw it three weeks ago in Super Bowl, and you saw it again tonight," said Ivan Rakitic, the Croatian in Barcelona's line-up, on Wednesday night.
"We made the impossible, possible."
Indeed, so. If you need to ask, you are neither a football fan nor a follower of world games.
Three weeks ago, the New England Patriots came from 25 points down to overhaul the Atlanta Falcons 34-28 at the Super Bowl in Houston.
On Wednesday in the Champions League, Barca turned around a 4-0 deficit after the first leg to beat Paris Saint-Germain 6-1 in the second leg - 6-5 on aggregate.
It eclipsed the greatest comeback most of us have seen, Liverpool's resurrection from 0-3 down to AC Milan to 3-3 and then to win the penalty shootout in the 2005 Champions League final in Istanbul.
Sheer guts. Indomitable leadership from Steven Gerrard.
Feb 5 in Houston, and March 8 at the Camp Nou had that same unconquerable spirit.
Barcelona versus Paris, the Patriots versus the Falcons are lifetime memories now. Yet, at least two other clubs encourage the suspicion that player power is becoming a rampant beast in football.
On nights like these, sports do not mirror life, they momentarily transcend it. Pulses race, hearts lift, and we are in awe of extraordinary never-say-die human instinct.
Why question that?
Aside from the displeasing sight of Neymar and Luis Suarez diving for penalties (and winning a couple), we have to ask about PSG's capitulation.
They won by four goals in the Parc des Princes just three weeks ago. Their pressing game hounded the Barca stars into submission through relentless tackling and closing of space - expunging even Lionel Messi, Neymar and Suarez.
What changed? Luis Enrique announced his intention to resign as coach after this season.
That seemed to free up Barca. The team scored 17 goals and conceded just two over the next three matches.
Wednesday's crowning glory happened, dare one say, without Messi and Andres Iniesta being at their very best.
Neymar, in particular, stepped up and showed that, if anyone dares even dream of stepping into such shoes, he has the desire and the ability.
Imagine it: A penalty kick in the last seconds of added time, and Messi, the captain and the catalyst, defers to the younger Neymar to take it, and score it.
Just one more extraordinary moment, the crowning one, on a night that few will forget.
We should certainly question the timidity of PSG and the tactical surrender before a ball was kicked. Those indicated the fear passed down from the coach Unai Emery.
He was hired by PSG's Qatari owners to lift the club's profile in this competition. He boldly went for it in the Parc des Princes but handed the field over to Barca at the Nou Camp. That, surely, will hasten Emery's departure from Paris.
But a saying as old as the game is that once players cross that white line, they are on their own. Where was the leader? Where among 11 were the men prepared to stand tall and at the very least resist Barcelona's charge?
Barcelona versus PSG, the Patriots versus the Falcons are lifetime memories now.
Yet, at least two other clubs encourage the suspicion that player power is becoming a rampant beast in football.
Leicester's miracle under Claudio Ranieri was over almost as soon as Andrea Bocelli sang Nessun Dorma to honour him at the King Power Stadium last May.
The unlikeliest Premier League champions were going down and out of the league until the owners listened to the players, and sacked Ranieri.
Hey presto, under Craig Shakespeare, the long-serving assistant to Ranieri and the previously sacked manager Nigel Pearson, those same players rediscovered how to labour and win. Leicester aren't safe yet, but beating Liverpool and then Hull City, both 3-1, means the club will trust in Shakespeare to see out the season.
So in just nine months, Ranieri descended from a god to a fall guy. Shakespeare, having been in the No. 2 role where a coach can be Mr Nice Guy, is now cast as saviour because the players like him - and will run for him.
You might expect that for multi-million-dollar salaries (and for simple pride) they would give their all anyway. It is, as players like to say, a short career.
Leicester came from nowhere last season, and won by running beyond the willpower of the opponents. Barcelona are a different story, a superior team that lapsed but refused to lose.
And then there's Arsenal. For half of Arsene Wenger's two decades in charge, the Gunners had real backbone, as well as style. For the second half, rather like PSG's second leg, Arsenal seemed to go so far and hit a brick wall.
The "Wenger must go" brigade are more vocal now than ever. Is it his fault that Mesut Ozil and Alexis Sanchez, the two most prized individuals Monsieur W. has spent Arsenal's treasure chest on, disappear when the going gets really tough?
Ozil did not play in either the loss at Liverpool last weekend or the 1-5 home humiliation against Bayern Munich on Tuesday. He is unwell, that is all we are told.
Sanchez was dropped against Liverpool after quarrelling with team-mates who felt he was not trying his best during training. Sanchez, the Chilean tiger who runs down lost causes on the field? Surely it is unthinkable that he is sulking while others run?
It is no secret that the two Arsenal stars are in a wage dispute. Their agents hear that Manchester United pay Paul Pogba £290,000 a week (S$500,000), so they want something commensurate for their men.
Arsenal, renowned as being rich but mean, say not a penny more than £200,000 a week for any man.
It might be coincidence, but Arsenal's collapse home and away to Bayern brings to a head the decision to trust Wenger, or to let someone else pay the wages, or the price, of modern player power.