It's all so grand and, well, epic. It's a full assault on the senses. Looking down on Celtic's opening group game from high in San Siro's vertiginous stands it was impossible not to be impressed yet again by the sheer scale of the spectacle. This tournament is football with all the bells and whistles on.
And then there are the little things. The fleeting, barely-noticed moments which subtly define the script of these huge nights. The big picture from Wednesday night was how calm and organised Celtic were when handling a formidable occasion. Not a formidable opponent - AC Milan are currently poor by their own standards - but a game and an arena which set a demanding and stern test of their nerve.
They saw far more of the ball than they ever previously have in an away game against one of the elite clubs in this competition. And making five reasonable chances to score amounted to about three or four more than many people expected. When manager Neil Lennon sits to watch footage of the 90 minutes again - he will do so more than once - there will be much to make him nod his head in quiet satisfaction.
It was a mature and cool performance which had none of the adrenaline rush of last season's Parkhead win over Barcelona but was, in some respects, more encouraging. If Celtic can travel to a venue such as San Siro and go toe-to-toe with such an established Champions League force, they have climbed a rung on the ladder as a club in Europe.
They performed on Wednesday night like players who trusted and were confident in themselves and each other. They have come a long way from the days when they would arrive in such places privately fearful of the sort of distressing humiliation suffered by Galatasaray against Real Madrid on Tuesday.
Hurt and disappointment was inevitable because Celtic had contributed so much and come so close to an admirable and enormously encouraging draw. When Lennon makes himself comfortable in front of a television, though, he will not do so simply to validate claims that his night's work was undone only by bad luck.
It is always tempting to attribute a defeat like Wednesday's solely to the team being unlucky, but that isn't quite the real story and nor does it enable a team to confront its issues, learn from them and continue to improve.
The little things undid Celtic in the end, the tiny decisions, actions and reactions which amount to only a miniscule fraction of their overall performance and yet entirely shaped and defined what they got at the end of it. Just eight minutes from the full-time whistle, Cristian Zapata struck a low shot which was heading wide until Emilio Izaguirre stuck out his right boot and gave it enough of a deflection to direct it inside Fraser Forster's left-hand post. That was unlucky, pure and simple. The ball could have gone anywhere.
But Zapata was allowed too much room and space to unload that shot from a dangerous position because Anthony Stokes had been sucked towards Mario Balotelli before the striker had released the ball into a pocket of space for Zapata. Shots from around there always carry the potential to take a deflection which can beat a goalkeeper.
Milan's second goal, three minutes later, had an element of luck, too. Forster did brilliantly to leap and claw out Balotelli's powerful free-kick and it was cruel on the goalkeeper that the ball flew back across his six-yard box, where Sulley Muntari reacted quickest to jab it into the goal. But Milan had four players racing in for that rebound and Celtic only one, Virgil van Dijk.
That was down to anticipation and reactions, not luck. The free-kick, too, had been awarded because Scott Brown had dunted Balotelli in an off-the-ball incident a few yards outside the penalty area. Frankly there was not much in it. Many referees would either have missed the incident or, even if they had seen it, decided no action was necessary.
Balotelli was constantly on his backside with his arms out looking for decisions. But on that occasion Brown was caught. He had a fine game overall but in that moment he needlessly conceded a free-kick which was within shooting range for a hugely-skilled dead-ball specialist. That was down to a momentary loss of discipline, not luck. These judgments are harsh, but so is the Champions League.
So much of Celtic's play, though, was positive and they know it. They were composed and intelligent with the ball, although their deliveries from the wings were poor. They looked like they were experienced, at ease and playing with clear heads. They had five reasonable chances: Charlie Mulgrew's indirect free-kick, Stokes beating Zapata but shooting wide, Georgios Samaras bending a shot past the post, Kris Commons putting Brown through, and Stokes hitting the bar with a free-kick.
Milan had four chances in addition to their goals: Balotelli's early volley at Forster, Alessandro Matri's flashing header, Antonio Nocerino's dipping volley and Muntari's close-range header over the bar when Celtic were exposed at the far post. So Milan had six chances and scored twice while Celtic managed none from five.
The late goals led to questions about whether Celtic would have been better to protect what they had in the closing stages and settle for a commendable draw. After 75 goalless minutes, Derk Boerrigter and then Teemu Pukki, two attackers, came on for Commons and Adam Matthews. "We were creating chances and had good spells of possession so we went for it," said Stokes. In truth the substitutions were of no consequence to the Milan goals. Although Pukki was caught on his heels when that pass came to Zapata, a tired Commons may not have been any closer to him.
Celtic lost their opening group games in 2006 and 2007 yet still qualified for the last 16 on both occasions. They have still to face the outstanding team in the section this year, of course. Given the probability of also losing the next game, at home to clear group favourites Barcelona on October 1, matchday three already looks like a must-win fixture at home to Ajax. "After the way we played against Milan they will be scared to play us at home in Glasgow," said Pukki. Even so, Celtic's campaign is likely to be shaped by whether they can take four points from Ajax.
The same principle will apply against the Dutch as it did in San Siro: in the Champions League even the strongest performance may be undone by a momentary weakness, so fleeting that it can be missed by the naked eye but become painfully apparent on the television replays.