A one-two at the 2022 Sao Paulo Grand Prix lulled Mercedes into a false sense of security with its unique zero sidepod design, which it carried over to 2023's W14.
Maybe, just maybe there was some goodness locked within the extreme concept that could make all the difference, but as soon as Lewis Hamilton drove it in February during a Silverstone shakedown, he knew the season was doomed.
"I remember it feeling exactly the same, and that definitely was not a great feeling. I really had high hopes," the Briton explained.
"In February, when we do a download of where the car is going, I was a little more apprehensive, because the previous year it was like: 'The car is amazing, it's unique, no-one's going to have anything like it.' And then we get to the first test
"So, I was a little bit more cautious when I was listening, and I was like: 'We will see,' and then the car had all these problems. I just knew it was going to be a long year."
A long year it was with just six podiums to his name, but this was a wasted year by Mercedes, one in which it seemed further away from Red Bull than ever and with drastic change going on behind the scenes, makes a simple bouncing back in 2024 virtually impossible.
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The end of the season
There was genuine optimism after a floor upgrade at the United States Grand Prix that Mercedes had taken a tangible step forward after abandoning the zero sidepods in Monaco.
Hamilton took second on the road in both Sprint and Grand Prix - before his Sunday result was expunged for exceeding the plank wear, but he followed up with a strong drive to second next time out in Mexico City.
But from there, Mercedes' season went into free-fall. Returning to Sao Paulo brought caution but the team was thumped as the W14 could not get to grips with Interlagos.
Slow-straight line speed killed chances of fighting for a podium, as Hamilton came home a lowly eighth, with George Russell retiring.
In Las Vegas and Abu Dhabi, Hamilton was dumped in Q2, and recovered to seventh and ninth, respectively as Mercedes stumbled across the finish line to nab second in the Constructors' from Ferrari.
Hamilton cut a resigned figure at Yas Marina, with a strong sense of him being there because he was contractually obliged to be instead of wanting to race.
After all, a 103-time Grand Prix winner and seven-time champion is not going to get revved up fighting for scraps and the odd podium. Hamilton is a winner.
It must also be said that this is not the Mercedes team of the glory years.
Put aside the car performance, this is not a team operating at the same level as it was in terms of trackside operations and back in the factory.
Firstly, there were a handful of instances in 2023 where Hamilton and Russell came across one another on track, including in qualifying in Spain where the latter knocked off some of the former's front-wing.
This was put down to a miscommunication by the team, which over the course of a season, can be expected. No team will ever be faultless operationally at every race.
But then it happened again in Belgium and the race in Japan, although contact was avoided on these occasions.
After the Nico Rosberg heat had been removed from the equation, Mercedes settled down and aside from Valtteri Bottas being told to cede position every so often, Mercedes was sharp with its trackside operations.
Sure there was the odd strategy blunder, but again, that's to be expected and the idea is to keep that to a minimum of one per season.
Mercedes was making mistakes it simply never did in its heyday - with key senior figures also leaving.
The Red Bull example
Take Red Bull as an example.
Adrian Newey is Chief Technical Officer, Pierre Wache is Technical Director, Paul Monaghan is Chief Engineer, and Jonathan Wheatley is Sporting Director.
Others such as Chief Designer Rob Marshall (McLaren) and Head of Aerodynamics Dan Fallows (Aston Martin) have been nabbed away, but the head of the technical structure has remained firmly in place.
As for Mercedes, since 2020, it has changed Technical Director twice, CTO twice, lost its power unit guru, strategy director and engineering director.
James Allison relinquished the TD role to be replaced by Mike Elliott, and made CTO, but in spring 2022, the two swapped roles with Allison taking on the more 'day-to-day' running of the technical team as TD.
Elliott then left his CTO role in October, with Andy Cowell, James Vowles and Aldo Costa also among those to depart.
That level of upheavel is not conductive to producing world championship-winning cars. For years, the stability of Mercedes' technical team was played up as a strength, but most of the pieces have departed. That will take time to bed in, time unfortunately not possible due to just how much Red Bull has been crushing the field.
It pressures Mercedes to find that magic, silver bullet and be back fighting for wins and championships, but this is a team in transition. The Brackley squad is currently in its 2010-2013 phase of building up.
Should the 2024 W15 also be a dud, so will the 2025 W16 due to the carryover expected as attention turns to the looming 2026 rules reset.
Mercedes is effectively two years behind Red Bull in its understanding of its car concept - and clawing that back will not happen overnight.
Who will be Red Bull's closest challengers in 2024? Let us know by voting in the poll and in the comments below!