Competing in the Boston Marathon is the ultimate goal for a lot of runners. For Beth Krapac, it’s been an evolving one.

In 2013, the first time she ran the world’s most famous marathon, it was pure joy. In 2014, it was about rehabbing a damaged psyche. Last year, she said goodbye to friends. This time, she’s going to compete and have fun.

The Vicksburg resident will run Boston for the fourth time Monday morning. It won’t be the last, but, she said, it feels like the first.

“I finally feel almost like I did the first time I went. I almost feel like it’s brand new again,” Krapac said. “I think I might be over that shellshock.”

The “shellshock” Krapac refers to is the psychological scars caused by the 2013 Boston Marathon bombings that killed three people and wounded 264. She finished the race about 20 minutes before the bombs exploded and was still close enough to the finish line to hear the explosions.

Krapac wasn’t physically injured, but being so close to such a traumatic event left her badly shaken for months. It wasn’t until she returned to Boston in 2014 and completed the marathon, she said, that she started to feel healed.

The energy and electricity surrounding the marathon, which includes nearly 40,000 runners each year and is the centerpiece of a state holiday in Massachusetts, was integral to the process.

“The atmosphere, it’s just electric. I went through something that was hard to deal with. I’m excited again,” she said. “I love to see new people and hear their stories. It never gets old.”

Last year, Boston was about friendship for Krapac. She went with running partners Tom Lilleyman and Bryan Register in their last lap together before Lilleyman, a Brit, finished an assignment with the Corps of Engineers and returned to England.

This time around, she said, it’s back to being about her. She’s ready to have fun again, and soak up the atmosphere.

“I’m going to be paying attention to other people’s T-shirts and where they’re from. That’s my favorite part,” Krapac said. “I have zero expectations but to finish and love it as much as I did in the beginning. After 16 or 17 miles, I’ll know if it’s a race I’m going to do or just participate in.”

When she first qualified for Boston, Krapac said, her goal was to make it there five years in a row. Runners have to achieve a qualifying time each year based on their age, and having to earn their way in is part of what makes competing there such a milestone.

Even before she runs Monday, however, Krapac knows she’ll be back in 2017. She acheived a qualifying time for next year’s race at the White River Marathon in Arkansas in November.

With that secured, Krapac has adjusted her goals again. This time it’s to keep running and returning to the race she loves.

“I’m going to go as long as I can. It’s my favorite race,” she said. “I said I wanted to go to it five years in a row. Now I’m starting to say I’ll go until I’m 60 and a body part falls off.”