Only Tottenham Hotspur can take the high spirits and enjoyment of five victories on the bounce plus another very good half of football and flush it down the toilet in 18 unacceptable minutes on the south coast.
Spurs had come into the encounter off the back of those five wins, with 13 goals scored and three conceded, and it was 15 goals scored in six games by 5pm on Sunday. Yet by the time the final whistle arrived, Ange Postecoglou was seething.
He made sure his Spurs players were well aware of that and his interviews after the defeat at the Amex Stadium were short and not particularly sweet. His club interview lasted just 76 seconds. It was only in his press conference where he opened up slightly more across eight minutes or so of questioning.
This should have been a very different day. Tottenham brought the confidence of those five wins on the spin to Brighton and tore their hosts apart again and again in the first half with Brennan Johnson, Timo Werner, Dejan Kulusevski and James Maddison running riot in and around the Seagull's box with Dominic Solanke pulling the strings in the pockets of space in a way that brought back memories of his England captain.
Spurs pressed aggressively and kept winning the ball back with 18 recoveries in those opening 45 minutes. Danny Welbeck called Brighton's performance in that first half "embarrassing" as the visitors got in behind again and again.
It was a pleasure to watch Tottenham in that first half and within just 18 seconds, the north London side should have been ahead when Solanke sent Werner away down the left but the German's ball across was too far in front of Johnson as he slid into the six-yard box.
Kulusevski then ran into the box and was denied by a last-gasp block. Within six minutes Spurs had another big opportunity as captain for the day Cristian Romero picked out Maddison with a ball over the top and despite excellent control from the midfielder, his half-volley was stopped by a great sliding challenge from Adam Webster, who would soon go off injured.
Werner had a shot deflected off target before sending in a header from a Pedro Porro cross that was saved by Bart Vebruggen only to hit Maddison and creep just over the line, pinging a message to the referee David Coote's watch. However, Porro had been marginally offside in the build-up.
Johnson was not to be denied his sixth goal in as many games. Maddison won the ball back in the Brighton half with help from Destiny Udogie, fed Solanke and the Tottenham striker played an inch-perfect weighted pass into the path of the Wales international who swept a first-time finish into that bottom left corner of the net that has become his best friend in the past month.
It meant the 23-year-old had become the first Spurs player to score in six successive games since Harry Kane more than half a decade ago. Johnson already has more goals than he scored last season and it's early October.
Just after the half hour mark came the warning that the away side should have heeded, Welbeck somehow sending a sliding effort wide from six yards from Kaoru Mitoma's excellent ball from the left.
Five minutes later, Spurs scored again. Tottenham played well around the Brighton press, Porro curling a ball into the path of Solanke, who turned, used his strength to hold off a challenge and fired a pass between the lines for Werner to race on to. The German faked to cross and instead stabbed it sideways to Maddison, who cut inside and hit a low shot that bounced through the hands of Verbruggen.
There was another Welbeck warning with a difficult header sent spinning just wide from Ferdi Kadioglu's cross, but Tottenham had a chance in the 43rd minute that we know now would have likely wrapped up the game.
Romero and Solanke combined superbly with the latter flicking the ball to Kulusevski and the Swede played a through ball that Johnson showed strength to run on to. However, for once he didn't go for that bottom left corner and instead sent a powerful central effort just over the crossbar.
Either way, Spurs went into the half-time break in a strong position, having dominated their hosts and firmly in control of the game.
Brighton boss Fabian Hurzeler made a key change at the break with Pervis Estupinan replacing Ferdi Kadioglu, who had struggled up against Johnson and Kulusevski.
Yet the Seagulls were helped by their generous visitors as Tottenham started making mistake after mistake from the off.
Pedro Porro allowed Mitoma to get in behind him, then told Romero with a hand in the air to hold off in coming across. It might have helped if he did because the Japan international's bouncing cross was completely missed by the sliding Micky van de Ven and Udogie made a complete mess of an attempted clearance, the ball ricocheting off the inside of his leg to Yankuba Minteh to gratefully fire home.
It's a cliche but the timing of the goal, so early in the second half, changed the dynamic on the pitch and inside the stadium. The Brighton fans came alive, the home side rediscovered their confidence and the Tottenham players started to shrink.
This was when Spurs needed their leaders to step up and they didn't. Only Vicario, who turned 28 on Monday, showed anything about him, making a low save from Mitoma soon after Brighton's first goal.
Tottenham could have got a third goal of their own still, Kulusevski sending a low ball into the Brighton area, agonisingly too far in front of Solanke as he burst towards the six-yard box.
In the 58th minute, Spurs showed all of the brittleness that many thought had been mostly dispensed with this season. It was too easy for Brighton, Mitoma handed so much space in between Bentancur and Romero, the latter eventually attempted a late, weak lunge at the ball.
That ball though had already been moved on to Georginio Rutter, who had run in between Van de Ven and Udogie. The latter's half-hearted challenge only pushed the Frenchman inside and he hit a shot across Vicario and into the same corner Minteh had scored in. Postecoglou shook his head on the touchline.
His players had crumbled but this felt like the moment when he should have responded by trying to change the obvious momentum shift with players from his bench.
If you're looking for Postecoglou to be a arm-waving, reactionary coach on the sidelines, that's just not who he is. Other than the odd shout, he mainly observes the game so he can make better decisions and little interjections to his players, but those better decisions did not come on Sunday.
Bentancur was just an onlooker by this point despite having had the midweek match off in Budapest. The attacking players had mostly become observers as Spurs failed to shift the ball up the pitch to them.
Postecoglou was missing the depth on his bench with players like Son, Richarlison and Odobert out injured, but something needed to change. Whether it was introducing Yves Bissouma or Pape Matar Sarr at that stage, or both, or whether it was to replace the shaky Udogie with Djed Spence.
Although not registered for the Europa League, a decision that still remains baffling, Spence had been left back at Hotspur Way unlike Sergio Reguilon - who was in the same position - when the team travelled to Budapest in midweek. The idea was that he could work and prepare in case he was needed should Udogie fail to return from his quad problem.
Yet Spence never even entered the fray, despite the Italian's clear struggles in the second half. Both Romero and Porro looked like players who had played the full 95 minutes in Hungary two-and-a-half days earlier but neither the rested Spence nor Radu Dragusin were looked to. Even Micky van de Ven looked off the pace at times despite having not played in midweek.
Even a youthful injection of energy in Archie Gray, excellent on Thursday night, or Lucas Bergvall or even Mikey Moore, following his exciting full debut in midweek, might have changed the momentum.
Instead, Postecoglou did something that goes against his belief system. He played it safe and that was exactly the opposite of what he needed to do in that moment.
His team were unable to repay his misplaced faith in them as eight minutes later, Brighton scored again after further errors from the same players.
Rutter received the ball from a Joel Veltman throw-in, turned Udogie inside out and nutmegged him despite having his back to him and initially heading away from goal.
Bentancur could have still won the next ball but passively almost looked to allow it to run out of play. It didn't, because Rutter showed the required determination and slid to scoop a cross into the six-yard box while Bentancur was yelling for a non-existent foul.
Romero had already strolled off on international duty by the looks of it. He initially grabbed Welbeck but then inexplicably wandered away from him so when the cross came in, he suddenly turned in panic, realising the Brighton striker had been left with a free header into the net.
Everything wrong with Tottenham's second half was exhibited in that goal. Weak in the duels, a lack of concentration and it wasn't just Romero who looked like he was already thinking about meeting up with his international team-mates.
There was a lack of leadership from all of the senior players when the team needed it the most. Romero and Maddison just muttered to themselves in the aftermath, Bentancur had been complaining about a foul that never was and Spurs looked devoid of inspiration.
Postecoglou could have changed that and his answer after game about making earlier changes than finally bringing on Bissouma and Sarr in the 79th minute after everything was done was not wholly convincing.
"Yeah I could have [made earlier changes]. But... all these things... are totally irrelevant to me. Substitutions and all those kind of things," he said. "If you're not competitive, it doesn't matter what you do, you're not going to get rewards, you don't deserve to win.
"We didn't deserve on our second-half performance, irrespective of subs or anything else, to get something out of the game, but I think if you do get something out of the game, you're falsely rewarded and I don't want to get falsely rewarded."
It felt more like one of Postecoglou's contrary answers, when he just wants to get his message across regardless of whether it makes any real sense or not.
Of course he would have wanted to get falsely rewarded if it meant three more points and being only five points off the top rather than eight. Get the win and fix the problems in the moment or afterwards, rather than lose all three points in order to make a point to the players.
That's exactly what happened at Coventry and he wasn't complaining about finding an undeserved win there.
On Sunday, Spurs created little as the second half wore on. Werner sent a shot over the crossbar, Udogie had an effort saved and Moore came on for the final minutes and embarked on a couple of promising runs but ultimately Brighton looked more threatening that the visitors did.
"We didn't do what you need to do at this level, it's kind of non-negotiable. We just weren't competitive. We didn't win our duels, we lacked intensity, we didn't deliver the things you need to at this level, the basics of the game, and paid the price for it," said Postecoglou.
"Not really sure [if there was complacency], but wherever it comes from, it doesn't really matter, it's irrelevant. It's unacceptable at the end of the day. You can kind of understand that you're not going to win every game, but there's the manner you lose games and that's the first time since I've been here that we've lost the game in that manner. And like I said, unacceptable."
When asked what he can do about it, he responded: "There's a lot I can do about it. That's why I'm in the role. If I couldn't do anything about it I'd get somebody else to sit here."
Maddison spoke after the game and pointed to the obvious phrase that came to mind.
"A game of two halves - you couldn't get more of an obvious game of that phrase. The first half we were dominant and at two goals up in the second half we were really poor and didn't deal with the adversity of them scoring early very well," he said in his club interview.
"Well that's an understatement, we dealt with it very poorly I think. Just couldn't weather the storm, couldn't grind it out. They scored three goals from three attacks and we need to be more solid in that moment of adversity."
He added: "Being 2-0 up in the Premier League against any side is decent enough. We just weren't good enough in the second half. They scored early, which is always disappointing, but you've got to deal with it a lot better than what we did. It felt like we lost control of the game, the crowd got behind them like we knew they would if they scored, but we just didn't deal with the attacks.
"They got in too easy down the sides, we weren't aggressive enough. All of a sudden you find yourselves 3-2 down and a lot of work to do.
"It's not enough, 45 minutes in the Premier League. Teams are too good, there's too much quality. You can't just let off after 45 minutes and we've been punished for that today."
This collapse will feel eerily familiar to Spurs fans and they were notified after the game by the kind people of Opta that this is the 10th time that Tottenham have lost a Premier League game in which they led by two or more goals. They are the first club to reach double figures for this with at least three more than any other side in the league's history. Most of those of course came long before Postecoglou's time.
There needs to be some context of course on this occasion. Spurs did come into the game off the back of those five victories on the bounce, then an excellent first half and a young team going through a rebuild is going to have the odd 45-minute horror show like this.
Postecoglou bristled when it was put to him that after a couple of positive results there might have been overconfidence among his players at half-time.
"Look, it's not a couple of positive results. It was five wins, let's just keep things in context here," he said. "I understand the extremes of what we do. What I'm saying is that we didn't do the basics of everything we've done to get to this point, good, bad or otherwise.
"Even when we didn't win at Newcastle, we played well and fought hard to the last second to win that game of football. We didn't do that today and every time we've played that's been an element of our game but I didn't see that today.
"Why has that happened? The reasons, we can go into a million different aspects and in the cold light of day there may be some logic to it and it may be what you're saying. Again for me that's irrelevant. It's for me to address and fix and the responsibility falls at my feet and that's what I need to do."
Postecoglou is right in that this defeat will now get blown out of proportion due to the painful nature of it and Tottenham's run of five wins will be made light of.
The impressive win at Old Trafford will be downgraded because Manchester United will be seen as poor, even if they did draw at Aston Villa on Sunday and should have won there with a last-gasp attack.
Brentford will have been an easy team to beat, even if they've only lost twice this season in narrow defeats to Manchester City and Liverpool. Winning with 10 men for much of the Europa League game against Qarabag will be dismissed, as will a victory at Ferencvaros even though Spurs had only won one of their previous nine European away games.
Coventry is the one game that there's little argument that Tottenham were dreadful in against a Championship side, even if they did eventually muster the character to snatch an undeserved win.
Brighton themselves had not lost a single game until the previous weekend's defeat at Stamford Bridge, but none of that excuses Tottenham's second half performance at the Amex Stadium. It does though place it within the context of the team's performances this season which have mostly been good and moving in the right direction.
What irks the Spurs fans sometimes and draws mockery from pundits are Postecoglou's quips for the cameras and there was another one before kick-off that came back to bite him.
He was asked by Sky Sports ahead of the game how Tottenham could keep the game controlled in what many expected to be an open contest.
"We don’t," he replied with a grin. "Let’s keep it open, that way we entertain everyone and hopefully get the result we want.
"We certainly want to play an expansive game and be really positive, and Brighton try to do the same thing, so it should be a good game."
The first part of that quote was always going to be used when Tottenham threw away their two-goal lead to lose the game.
Postecoglou likes to make a big thing about football being entertaining and people enjoying watching the games, yet of course he also wants Spurs to control matches. He's often speaking about that so this answer was a slightly flippant crowd-pleasing one which backfired.
Ultimately this game was lost through a collection of individual mistakes, a lack of leadership on the pitch as Brighton started to find their foothold and also Postecoglou's reluctance to turn to his bench to change the momentum of some of the performances.
When asked if he had given his thoughts to his players after the game, he said: "Yeah, feedback is always what I believe. I don't hide things. I'm sure the players are disappointed, but I don't really care about that. They should be disappointed.
"Our supporters are disappointed, I'm disappointed, but I want them to understand football is not about losing a game of football, that happens. The disappointment comes from us not doing the very basics of what's expected at the highest level from a competitive standpoint.
"That's a real stark reminder of what elite sport is about. The core of it is competitive. If you're not competitive it doesn't matter how good you are or how good you think you are, you're going to trip up. We didn't do the things, aside from the football, we didn't do the things that we've prided ourselves on to get to the position we're in."
Upon being asked if he learned anything new about his Tottenham players, he said: "I don't know if I learned something new but I certainly experienced something new. With all these things, straight after a game you're emotional about it.
"That's probably the most disappointing loss I've had since I've been here, in terms of the way we went about it and it's something I need to assess."
Tottenham often leave their fans feeling glum ahead of an international break, meaning two weeks to digest a negative end to three far more positive weeks. This was a bump in the road, but it's one that Postecoglou and his players will need to learn from with two Premier League derbies in quick succession to come after the break.
Maddison called the second half display 'two steps backwards' after all of the recent progress and he was right. He and Spurs' other captains must lead the way in heeding the tough lesson dished out to them on the south coast and ensure it does not happen again.
Potential international injuries aside, Postecoglou will have more players returning to fitness for the coming games and he's going to need options aplenty to turn to and more trust in his bench if Spurs are to quickly return to those winning ways.
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