Did you know Dale Earnhardt Jr. was a smoker? Neither did we

In an interview with Forbes, NASCAR great Dale Earnhardt Jr. opened up about his struggle to quit smoking - a habit he reportedly kept fairly quiet for more than 15 years. 

In the interview, published on Tuesday, Earnhardt tells Forbes that he was a smoker for more than a decade and it took him several attempts to stop. As of 2019, he's been smoke-free for six years. 

In 1990, when NASCAR was gaining momentum, about 30 percent of adults in North Carolina said they smoked almost every day. That number dropped to 17 percent in 2018.

When Earnhardt Jr. won the NASCAR All-Star race at Charlotte Motor Speedway in 2000, the event was called the Winston. It was named after the cup series at the time.

In 2003, the RJ Reynolds Brand put a checkered flag on sponsoring the sport. The U.S. Food & Drug Administration soon followed, passing a law forbidding cigarette and smokeless tobacco sponsorships in the sport.

Earnhardt told Forbes in the interview that was by phone on Saturday that, "It was something that I picked up as a habit while hanging out with my friends, all my friends smoked. It started out as a small habit I didn't think was serious, but became a full-blown habit over those 15 years." 

While the smoking sponsors within the sport have fizzled away, tough habits can be hard to break, even for drivers. It wasn't until later Earnhardt said the habit became something he was extremely afraid of, affecting his health and quality of life. 

According to Earnhardt, his smoking habit wasn't necessarily a closely guarded secret but it wasn't something he advertised either. For more on Earnhardt's journey to being smoke-free, please click here