It has been more than 6,000 days since Jonathan Brain was diagnosed with leukemia, and almost 17 years since the Dublin resident was declared cancer-free.

The more time that passes, Brain, who is participating in his seventh Pelotonia, acknowledges there are times it seems like it never happened.

"Sometimes, it seems like a dream," said Brain, 46, a Westerville native who rides for the Cardinal Health Cycling Team. "You get to this point, and it's far enough out that you start to wonder whether it really happened in the first place.

"Enough time has passed that it seems like a dream, but at the same time, I am always looking over my shoulder. That specter is always hanging over me."

Thinking he had the flu Dec. 22, 1999, hours before he would have worked his usual third-shift job, Brain drove himself to an urgent-care facility. Like many others at the time, he had been anticipating Christmas and the year 2000, but that night would change his life.

"Going up a flight of stairs took way more out of me than it should have," Brain said. "They did some bloodwork and came back and told me something wasn't quite right.

"I went straight to the emergency room (at Mount Carmel St. Ann's Hospital in Westerville), and after about three hours, I got the news. It was probably 3 or 4 in the morning before I got to talk to a doctor.

"That news knocked me over."

Brain spent more than a month at the James Cancer Hospital and underwent chemotherapy and other treatments for eight months before his doctor pronounced him cancer-free.

Despite not being a cyclist, Brain rode 25 miles in his first Pelotonia in 2011. He used a mountain bike because that was what he owned.

"It was over before I knew it," said Brain, who works in the ethics-compliance department at Cardinal Health. "You're riding with 5,000 or 7,000 other people and you're so charged with that energy that when you get to the finish line, you're like, 'That's it? It's over?' You almost want to go farther. Biking is my summer pastime now. ...

"It's something I've always liked to do, but my body was not always compatible with the bike."

Brain rode 100 miles two years ago, and this year is taking the 25-mile Columbus-to-Pickerington route.

Even if 17 years ago seems hazy to Brain in everyday life, it does not whenever he is on his bike.

"For me, being a survivor is living proof of why this event exists," Brain said. "I am just glad to be here and able to ride. I want to come out here and be able to pay it forward to somebody else. ...

"I hear so many people get that diagnosis, and when you hear that, you relive it. While you are riding, there are constant reminders. Every day, there are reminders."