Tony Stewart turns 41 in May, and he is a better race car driver today than he was at 31 when he won his first Cup championship.
Gene Haas, Stewart's partner at Stewart-Haas Racing, may have explained it best when he was asked about Smoke during a postrace interview Sunday after Stewart's win at Las Vegas Motor Speedway.
"He's as calm as I've ever seen him," Haas said of Stewart. "He's composed and very confident in what he's doing. He's just as smooth as glass out there. He doesn't hiccup.
"He's a phenomenal driver with great throttle control, and he's very adept at figuring out what's going on in a race."
Some of those things always have been true about Stewart, but it's his calmness now that's so different from his demeanor earlier in his career.
Stewart still gets a jab or two in at the media every now and then, but we wouldn't know it was him if he didn't.
During an interview session Friday, one reporter asked him if he would jump off the Stratosphere the way Carl Edwards did last year.
"No, but I'd like to throw you off," he said.
That's the Tony we all know, but he did say it calmly, something he wouldn't have done years ago.
Even new crew chief Steve Addington is surprised at how easy-going and worry-free Stewart has been since Addington arrived.
"When Tony feels good about the car, I'm still questioning it," Addington said after Sunday's race. "He's just like, 'Relax dude. It's going to be all right.'
"I get nervous and I'll text him a couple of things. He just texts me back and says, 'Go ahead and do what you feel like you need to do. We're good.'"
Stewart displayed his calmness at Phoenix two weeks ago when he couldn't restart the engine late in the race after turning it off to try to save fuel.
When asked moments after the race what had happened, Stewart shrugged it off.
"I don't build these things," he said calmly. "It's not my department. You're asking the wrong guy."
In years past, that was a meltdown moment for Stewart. But time tends to mellow a guy, as do three championships.
Stewart said he didn't make a big deal out of the Phoenix issue when he talked to the guys at the shop last week.
"I didn't ask any more questions," he said Friday at Las Vegas. "I figured I didn't need to know. I figured they have addressed it. They told me that they knew what it was, so that was good enough for me."
That statement is the textbook definition of delegating authority and letting your employees do the jobs you hired them to do. It's the reason Stewart is successful as a team owner.
Stewart also could have snarled and shown his surly side when asked over and over about letting Darian Grubb go and watching Grubb lead Denny Hamlin to victory at Phoenix.
He didn't. Stewart took the high road every time, saying how happy he was for his former crew chief and how hard it was to part ways. The subject came up again after his win at Las Vegas.
"You guys know I don't worry about what everybody else says," Stewart said. "I'd like to think over 32 years of racing we've made some pretty decent decisions. From Day 1, I told Steve we're going to have fun and take what it gives us."
Whether that fun leads to another Cup championship remains to be seen, but Stewart appears content to accept whatever the future holds.
He is a calm man, believe it or not. More than at any other time in his life, Stewart is comfortable in his own skin.