JACKSONVILLE – Getting better doesn't mean you automatically win.

The Jaguars surely knew that already, but they relearned it in a painful way in the regular-season opener Sunday.

Panthers 20, Jaguars 9.

That was the frustrating, disappointing final of the 2015 regular-season opener. And if you left EverBank Field feeling dissatisfied Sunday, you weren't alone. This one was disappointing.

It was dissatisfying.

It was those things and many more things that aren't sunshiny. Because on a sun-splashed, perfect-for-football day in front of 60,773 at the 'Bank – a day that began with sunshiny optimism after an offseason of additions and improvement – the Jaguars on Sunday lost one they could have won.

"The feeling right now is uncomfortable in our locker room," Jaguars Head Coach Gus Bradley said. "It's not a good feeling because I think we felt like things under our control – dropped passes, mistakes, critical errors – kept us from getting over the top in this game."

Those words, some of Bradley's first in his post-game news conference, summed up a lot about this loss. The Jaguars, while improved in many areas, are not yet a team that can make momentum-changing, point-costing errors and expect to win.

This game was about those sorts of errors and it was about unfulfilled opportunities. It was also about turnovers. When you're writing that, it's usually not good for the team in question.

"It's not the way you want to come out and start the season at all," quarterback Blake Bortles said. "We're not going to sugarcoat it … It wasn't good enough and we're going to have to do better."

This wasn't last year's Jaguars, and it wasn't 2013's Jaguars. The stats may have said otherwise, but this team looked more competitive. It looked better in a lot of areas.

But because of mistakes, it wasn't enough to win, and that's what matters now.

"I'm surprised we didn't play better," Bradley said.

Bradley went on to say he thought the defense played "pretty good," as did the special teams. He said he saw some good things from the offense, too.

"I just thought it could be more of complete game," he said. "We could have played more consistent."

He was absolutely right on that point, because this wasn't a game when the Jaguars got manhandled in any particular area. The thought entering the game was that this roster had improved to a point where it could stand toe-to-toe with teams, particularly with teams not exactly among the elite.

The Jaguars stood toe-to-toe a lot Sunday, and they did a bunch of things early that could have had them ahead at halftime, maybe even relatively comfortably so.

But three times the Jaguars dropped passes of at least 15 yards. And although Allen Hurns made a highlight-reel, sideline catch that set up the Jaguars' only touchdown he also fumbled in the second quarter at the at the Panthers 17. That took away points.

That rookie kicker Jason Myers' day hurt goes without saying. If the Jaguars can't afford three key drops by receivers, they certainly can't afford missed extra points and missed 44-yard field goals. Those four points loomed large throughout what was mostly an eight-point second half.

What hurt most, of course, was Bortles' interception that cornerback Josh Norman returned for a 30-touchdown early in the third quarter. Bortles afterward called the play "obviously a bad throw, a bad read."

Bradley said from his view it just looked like Norman undercut a flat out route by running back T.J. Yeldon, and what Bradley said he heard in the head set sort of summed up the play.

"That's a young mistake by Blake" was what Bradley said he heard.

That's what it was, and that isn't completely unexpected. As good as Bortles looked during the preseason – and even on Sunday he still looked improved – he is a young quarterback. Young quarterbacks will make errors. They'll make ones that cost you games. Don't write Bortles off because of that throw early in the third quarter.

As Bradley pointed out, the Jaguars were still just eight points behind at that point, down 17-9. Twenty-four minutes remained and as Bradley said, "We could bounce back from that."

They didn't bounce back, and that was surprising. It was surprising, too, that an offense that moved effectively throughout the preseason never seemed to get a rhythm Sunday. And being down by double digits in the fourth quarter wasn't what this team expected Sunday. That was surprising, too.

"We had to have a game like this to see where our bar is, where we're at, and how much further we need to go," Bradley said.

Where is that bar? How much further do the Jaguars have to go? That remains to be seen. In time, the loss to Carolina Sunday could be seen as an aberration, one in which a slew of mistakes cost an improving team a winnable game.

That's what the Jaguars believe they are – an improving team – and it's what they looked like in preseason.

On Sunday, they looked like a young team with a lot of learning left to do, particularly on offense. That doesn't mean they're a bad team, and it doesn't mean they haven't improved.

But it does mean they have to eliminate mistakes to keep these frustrating, dissatisfying feelings from ruining otherwise sunny Sunday afternoons.