In part, the 2012 Cup season will be remembered for Dale Earnhardt Jr.'s exit from the No. 88 Chevrolet because of a concussion.

In retrospect, Earnhardt regrets not taking a hiatus from competition sooner than he did.

On Aug. 29, during a tire test at Kansas, Earnhardt sustained a concussion in a hard crash. He knew he was hurt but decided to keep the severity of his injury to himself.

A subsequent crash at Talladega caused a second concussion and forced Earnhardt from the car for two races.

"I think I should have taken the first concussion more seriously," Earnhardt said Thursday, after being honored as the sport's most popular driver for the 10th straight year. "I think I should have been smarter about it the first time, when we crashed at Kansas. I didn't feel good, and I started getting nauseous after that.

"I knew right then, for damn sure, that I had a really bad concussion. I wish I would have taken that more seriously. I don't know if it would have changed anything. It's a tough decision to make, going into the Chase. I'd dealt with concussions before, and I thought that I'd just drive through it, and it's be over in a couple of weeks…

"But I wasn't lucky enough to avoid another accident, so I feel foolish in that regard, that I was careless."

Missing two races cost Earnhardt any possibility of winning his first championship and dropped him to 12th in the final standings.