Enjoy him while you can, NASCAR Nation.

Savor this Sunday’s Daytona 500. Relish it.

It might be the last one Dale Earnhardt Jr. ever runs.

NASCAR’s most popular driver has made it clear, he will not beat his brains out — literally — in order to continue racing.

“Of course I’m human and I’m going to be concerned,” says Earnhardt, who sat out much of last season trying to overcome serious concussion issues.

There’s a reason Earnhardt said Wednesday at NASCAR’s Media Day that he would love to win the championship this season and walk away while he’s on top. Translation: He just wants to be able to walk away — period — and not stumble away like a punch-drunk boxer.

“Hell, yeah. I would definitely not want to come back and try to race anymore if I won the championship; I’d be outta here,” he said and laughed.

And then he turned serious.

“You know, I’ve always wanted to win a championship so badly. We’ve worked so hard to come back from this injury. To come back and win a championship, it would be hard not to hang it up.”

Even more than the other drivers who risk their lives every day blazing around the nation’s race tracks with their hair on fire, Dale Jr. has seen his own mortality flash before his eyes. He has driven as thousand times by the spot where his father died on this track. Now, more than ever, he, too, is thinking about how his next race might be his last.

Even though his doctors tell him he is likely not risking further injury to his brain by returning to the track, there are no assurances. When it comes to concussions, even the most astute neurosurgeons are often providing just educated guesses.

Earnhardt’s head is sort of like Tiger Wood’s back. If the best orthopedic surgeons in the world often can’t figure out what causes back pain, think of the added complexities neurologists face when dealing with brain bruises.

As Dale Jr.’s own doctor told him, “Concussions are like snowflakes. There’s no two that are the same. Me and 10 other people in here could have the same exact event, but experience completely different symptoms.”

Earnhardt’s symptoms were so bad last year that he literally saw his career flash before his eyes — his blurry, bleary, fuzzy, foggy eyes. His newlywed wife Amy had to drive him around and he couldn’t even look out the window of her car without getting dizzy and nauseous.

“My eyes were jumping around in my head real bad, just walking down the street or riding in a car,” Earnhardt says. “A road sign was jumping around so I couldn’t even read it. I was scared to death that I was going to be stuck with that all my life.”

He could barely put one foot in front of the other without tripping. He became depressed and irritable. He sat out the final 18 races of the season and said there were days during the recovery when he felt he would never race again.

Slowly but surely, he started regaining his vision, his motor skills and his desire to drive again. But he has made it very clear, he would not be back if the doctors told him he might be risking his long-term health. He just married Amy in December and talks longingly about wanting to be a loving husband, a future father and a caring family man.

Even more refreshingly, he’s opened up about his medical issues and shed some light on his darkest days. He’s talked to reporters in-depth about his fears and doubts. And he’s forced other drivers to look in the mirror. Danica Patrick, for instance, revealed on Wednesday that she’s probably had a dozen concussions during her career.

“It makes you think and pay attention to yourself,” Patrick said. “There’s nothing better than having somebody like Dale Jr. going so far as to get out of the car for as long as he did and saying, ‘Hey, I have a problem,’ because it makes (the option) more available for everyone else.

“I think we like to sweep it all under the rug as drivers like we feel fine and nothing is wrong, but it’s our life. If someone told me if I have another wreck that I could have a serious (medical) problem, I would be out. I love what I do, but I love lots of other things and I also love life, and I’m too young to have it be over.”

Dale Jr., it seems, has made others realize that just because you have racing on the brain doesn’t mean you have to give up your brain to racing.

Even more impressively, he has announced he will donate his brain to research.

He is his father’s son, but he doesn’t have his father’s tough-guy demeanor.

Dale Earnhardt Sr. made NASCAR safer when he died; Dale Jr. is making it safer while he lives.

Dale Sr. was known as the Intimidator; Dale Jr. should be known as the Educator.

His brain has already made NASCAR a much smarter sport.