Not for the first time, testing brought to mind the old Johnny Nash song, as the penultimate day of running definitely posed more questions than answers.
Or did he?
While he posted the fastest time of the day, his best time remains 1.109s off the best posted by Valtteri Bottas last Friday.
And at a time we were all wondering if perhaps Mercedes was correct and Ferrari is running its power units at a lower performance level than its customer teams, the picture was further confused when the teams began their race simulations in the afternoon.
"This was a good day in terms of the number of laps we managed to do," said Vettel, "as well as for the fact that we got through the programme we had set ourselves. Having said that, I don't think today's times mean much, because, out of the five days of testing we have done here so far, today's track conditions were definitely the worst.
"The overnight rain had washed away all the rubber put down on previous days and, on top of that, the wind got much stronger right from early morning, making it harder to drive. I think we have done a good job, concentrating mainly on what we had to do, without thinking too much about lap times.
"We won't really get a clear picture until Melbourne, but maybe not even there, given that the track is pretty unique. Overall, I'm pleased with the way testing went."
Just two laps into Vettel's race sim, Lance Stroll headed out in the Racing Point, and it's fair to say that the pair's times were comparable. At one point the pair were running close together, and such was the similarity in pace that one has to wonder if what we were witnessing was a weaker than expected Ferrari or a stronger than expected Racing Point.
For good measure, Stroll posted the third best time of the day, just 0.277s off Vettel's pace, on the C3s.
"We put in a lot of laps, my neck's going to be a bit stiff in the morning!" said the Canadian. "We got held up a bit by the rain in the morning and it was really windy in the afternoon, which compromised running for everyone a bit. But all-in-all some solid running and the car felt pretty good out there.
"It's testing, so we don't know what everyone else is doing," he continued, "but what matters is that we've been making progress over the past couple of weeks. We've definitely improved the car in terms of the balance on both short and long runs and the team have done a great job of dialling it in more and more as the days have gone by. It's a bit weird having less time in the car compared to previous years, but I'd say this has been my best pre-season so far. I'm feeling fresh from all that off-season training and ready to go racing."
Pierre Gasly, who had spent the morning on longer runs, turned his attention to pace in the afternoon, and when he finally fitted a set of the C5s he went second with a 17.066, just 0.225s off Vettel's pace. With 139 laps completed it was a good day for the Faenza-based outfit.
"It was a pretty good and intense day," said the Frenchman. "The track was damp this morning which meant we had to do most of the work in the afternoon.
"We did over 100 laps after lunch which was great, and managed to do a race simulation and push the car a bit more to see what we've got.
"Compared to last week, the conditions were slightly more difficult because of the wind which made the car challenging to drive at times.
"There are a couple of areas we need to improve on," he admitted, "but I can say it was a decent test for me. I know we have a bit more left in our pockets and I'm pretty pleased with the car, however, Melbourne is quite different from Barcelona, so even if I don't want to get too excited, I'm pretty confident going to the first race."
Stroll's pace, combined with the fact that he competed 130 laps, is further proof, as if it were needed, that Racing Point is not only a serious contender for best of the rest this year, but could be hassling Ferrari and Red Bull in the right conditions.
However, amidst existing rumblings about the legality of the RP20, today's show isn't going to calm the waters at a time it is feared the situation could get nasty and legal come Melbourne.
While Vettel and Racing Point hogged the headlines, one of the true stars today has to have been Nicholas Latifi. While his best time - good enough for fourth - was missed by the TV cameras, the fact the Canadian was able to complete 160 trouble-free laps further suggests that the Grove outfit has made serious progress.
"Overall it was a positive day," said the Canadian, "and I got to experience the car in both trims that you would in a race weekend.
"We focused our morning on performance runs and I was finally able to feel the limits of the car," he added. "Unfortunately, the track conditions this morning hampered our running, and from that point of view our performance simulations weren't as representative as I would have liked.
"In the afternoon we moved on to conducting our race simulations and I was able to get a lot of laps on the board.
"I think today went well, we had no issues and I was able to make up for the lost mileage from the previous days. This was the last time I will have had the chance to drive the car, I am looking forward to arriving in Melbourne and making my debut with the team."
The Woking outfit is one of several teams yet to show what it can really do, though Carlos Sainz promises that he will be going for a decent time tomorrow.
"I'm happy with the day," said Norris. "We did a lot of laps, a lot of short runs and almost a full race run. We gained a good understanding of the car, both alone on track and following other cars - a bit of a mix really, which is usual at testing.
"It was a decent way to end the pre-season for me, giving us a good understanding of the areas to work on as we prepare for Australia."
At a time there is much talk about sandbagging, perhaps it is only right that some teams continue to tantalise us by holding out on their hot laps.
It wasn't the best of days for Red Bull, the Austrian team only completing 92 laps in total. Max Verstappen had a troubled morning, spinning twice, the second occasion seeing him beached in the gravel and causing one of the day's several red flags.
In the afternoon Alex Albon completed a further 61 laps, but, as was the case last year, the Austrian team is sticking to the mediums.
"It was a bit of a shame with the weather," said Verstappen, "so we couldn't really run as much as we wanted, but overall it was positive.
"We spent time driving with the aero rakes, gathering all the data we could and everything went well. Every day we are improving, learning more, and that's exactly what you want from testing.
"It was never the target to run as many laps as last week. I think we have done our long runs and now it's about checking parts and trying different things. It all takes time and the end result is fewer laps, but I think we tried everything we wanted to today.
"Regarding the spin I had this morning, I had a look back at the footage and I just clipped a little damp patch, which I didn't see, but yeah, I think I just tried to take a little too much road on the entry!"
"This afternoon was a little bit disrupted," added Albon, "mostly because of the wind, which was tricky, and it was hard to get a good read on balance, but otherwise it wasn't too bad today.
"Everything's going well, but of course we need to look at the data as it was not so easy to do direct comparisons today. I think tomorrow the weather should be a lot better. There's still work to do and that's what tomorrow is about – fine-tuning and chipping away at it.
"We have done a lot of running and I think the positive thing is that we know the direction we're happy with. We have got a good base heading into the start of the season."
On a day when running was already compromised as a result of overnight rain that left the track damp, Valtteri Bottas was able to complete 47 laps, despite being one of several drivers to spin after either clipping a damp kerb or getting caught out by the wind.
Late out in the afternoon, teammate Lewis Hamilton had only completed 14 laps when he stopped on track, necessitating the fourth red flag of the day.
The problem was subsequently found to be an oil leak, and while no big deal on its own, it follows a similar issue for Williams, while the Grove outfit and Bottas have also suffered problems with the Mercedes MGU-H, all of which required engine changes.
"Lewis stopped on track due to an oil pressure anomaly, which made the engine shut down as a precautionary measure," the team subsequently confirmed. "We will keep investigating further but unfortunately that concludes our running for the day."
"I only got 14 laps in today," said Hamilton, "but during those 14 laps, everything was feeling fine.
"It's obviously not ideal that we didn't get a full day of running in and we experienced this issue, but there are lots of learnings to take from today. Rather than looking at the negatives, we've discovered some things we need to work on, and we'll keep pushing hard to resolve them and keep working away.
"I'm looking forward to being back in the car tomorrow morning and adding to the mileage we've already achieved."
"Obviously, the running today in the morning was slightly limited with the wet weather," added Bottas. "But we got a couple of runs in with the intermediate tyre, which is always useful. We had a good feeling on that tyre in those conditions and gathered some good information. The session was slightly disrupted by red flags, so we missed some of the test items we planned to do. However, we still completed a few good long runs and set-up work - so got some decent mileage in.
"I have one afternoon left in the car, which I'm really looking forward to. I feel pretty ready to race. We had a few issues here and there, but the team is working on resolving them and we'll sort everything out for tomorrow."
Like Mercedes and Red Bull, Renault had both its drivers on duty, Esteban Ocon this morning and Daniel Ricciardo this afternoon.
For both drivers it was a fairly anonymous day, and while both were over 1.1s off the pace, on a day the likes of Williams was completing 160 laps, 96 laps between them seems a little poor.
"Overall, it's been a very positive day," said the Dane. "We were delayed a little bit at the start of the day as we chose not to run in the wet conditions at all, we simply did our install lap then waited for things to dry.
"We got a full race simulation in at the end of the day, which was nice to get completed before we head to Australia. It's always very interesting to get your first feeling of how the car evolves over a race distance.
"Today allowed us to experience that for the first time and it was very positive. We'll keep working tomorrow and look ahead to Australia."
With the clock ticking down, the updates are appearing on a more regular basis, and among these was a new rear wing on the Alfa Romeo.
Unfortunately, Antonio Giovinazzi was one of this morning's many spinners, though in his case it involved clouting the barriers... with his rear wing. Cue extra work for his crew and a lack of vital running for his team.
"It was a challenging day from the start," admitted the Italian. "I did a mistake in one of my first runs, when the track was damp, and that cost us some time in the morning. When we went out again in the afternoon, the yellow flags ruined our qualifying simulation and we couldn't really do a lap.
"At least we were able to follow our long runs programme," he added, "the wind was very strong and we struggled a bit, but we were able to get it done.
"It was the last time in the car before Melbourne for me: I am satisfied with these two weeks, we need to focus on our job and try to be strong from the start in Australia."
For Vettel, Norris, Gasly, Stroll, Giovinazzi and Latifi, today marked their last day of running before FP1 in Melbourne. Despite what they might say in the summaries and press releases that follow, only they will truly know what sort of shape they and their teams are in.
McLaren and Red Bull are among those still to show us what they have up their sleeves, while Renault and Haas have us wondering if they have anything to show, and then there's Mercedes, which, at a time Williams has suffered three engine changes in as many days, has today shown the first possible chink in its armour.