William Byron has learned what it is like to struggle the past few weeks. That can be a good lesson -- a hard one, but a good one.

Byron, who turns 21 in November, is the youngest driver in an elite ride in the NASCAR Cup series. He raced just one year in the Camping World Truck Series (winning seven races), then won the Xfinity Series title last year. By the time he had entered the Xfinity playoffs last year, he already had been anointed to replace Kasey Kahne at Hendrick Motorsports.

His "welcome to the Cup series" moments have occurred in the past three weeks. He crashed at Daytona but was able to continue and finished 23rd. He then was running a couple of laps down but salvaged an 18th-place finish at Atlanta. Last week at Las Vegas, he finished four laps down in 27th. He sits 24th in the Cup standings.

That 18th-place finish at Atlanta was the hardest-fought 18th-place finish of Byron's career.

"It was rough," Byron said last week. "There is no doubt about it, it was a rough weekend, but we definitely learned a lot from it. Just to make it 500 miles and to know what that is going to be like and to know what I need to do to get to that point was the biggest thing for me.

"Once I kind of realized that, where we were as far as how our car handled and things like that, you just kind of reset your goals and just go from there to figure out what you can do to maximize the day."

Some would view that comeback as an accomplishment. Byron did not.

"I don't think it was very satisfying, but it's a starting point," he said. "I think it makes you appreciate when you go to a racetrack when you guys unload fast.

"We didn't really have that [at Atlanta], no doubt about it -- we kind of just were trying to get something out of the car. We couldn't get a lot of things to work, but I think that you learn from those weekends and you learn what it really takes to be successful."

For Byron, just having a tool such as a driver-adjustable track bar, which allows him to tweak the rear suspension from inside the cockpit, is new.

He still has to figure out what he needs and whether he should adjust the track bar, ask for other adjustments or choose a different line to drive.

The most common theme and adjustment for a driver to Cup comes with learning how to make those adjustments, especially in a field that typically has at least 30 quality cars.

"It's just like there are increments in the Cup series where there are five or 10 cars that are really equal and the margin is that small," Byron said. "It's a restart or getting on pit road. Knowing what things I can work on there is going to be critical, [as is] just knowing what I need in the race car to be better."

Byron is among the top young drivers in the sport. Many of them are in Cup, while Christopher Bell, 23, is in his first year in the Xfinity Series.

Bell, whose background is sprint cars, sees what Byron is doing at 20 and isn't worried that he has to match what Byron does. A driver must take the opportunity when it comes, but a driver such as Bell sees those younger than he is and knows his maturity and experience could count for something.

"I keep telling myself my maturity helps me, my age helps me a little bit," Bell said. "I'm not too worried about not being in Cup at 23 years old. My dream as a kid was to be able to drive a race car for a living, and I've been able to accomplish that for a long time now, since I was 16 or 17 years old. If I don't make it to Cup, my career will not be a failure. I'm not worried about it. I'm going to go out there and try to win races."

Justin Allgaier, a teammate of Byron's last year at JR Motorsports and a former Cup driver, said the adjustment for Byron is as much outside the car as inside the car.

Young drivers are learning the culture outside each racetrack -- where to go for commitments as well as for fun -- as well as what do on the track.

"William has done a great job," Allgaier said. "He's really talented. ... This sport, if you're talented and you're willing to put in the hard work, this sport will pay off on that. I think that's why you see both of those guys [Bell and Byron] being successful in having two completely different backgrounds."

Byron hopes that, once things start to click, he will rattle off successful finishes.

"I would say there is a lot of stuff to work on," Byron said. "I mean there is the pit road stuff, the green-flag stops, the length of the races and then just learning [crew chief] Darian [Grubb] and my guys to know what to do.

"I think we are going to get there probably quicker than people expect, but there might be some rough patches here and there."

Byron also has gotten used to a little bit of fame. He used to be able to go around town where the race was and go fairly unnoticed.

Now, he gets recognized in public. Part of that is from winning races, and part of that is driving the iconic Hendrick No. 24 car that Jeff Gordon made famous.

"It is definitely flattering and it's cool that people are following what we are doing, and I would say the biggest difference is the No. 24 fans that have kind of come over [to me]," Byron said.

"I was walking in the media center and there is a lady with her No. 24 forever shirt on, just those things are different for me. I'm trying to understand that and understand how I can make my own name in it and really be my own person."