Name a city, any city. Name Baltimore, Pittsburgh, or Philadelphia and I think of high-rise buildings, crowded city streets, and a place this country boy doesn't want to be. Name a city, any city, that is, except Boston. Name Boston and I think of something else.

This past April marked the 112th running of the historic Boston Marathon. To run Boston, you need to do more than pay an entry fee. You have to qualify by running a marathon faster than the challenging qualifying times. Though the standards have been softened over the years to allow more runners to enter, only the best earn the privilege of running on the streets of Boston.

The first Boston Marathon that I remember watching was in 1982. The world record holder, Alberto Salazar, dueled with Dick Beardsley, a relatively unknown dairy farmer from Minnesota. I watched in awe as they ran sub-five minute miles, the giant versus the underdog. Beardsley tried to run away, but he could see Salazar's shadow beside him. As the miles passed it was clear that neither man was willing to relent. It was only in the final meters that the outcome was decided-the king would keep his crown. But, Dick Beardsley taught me a lesson that day. To truly find out what you can accomplish, you have got to push yourself into unknown territory.

A couple years later I entered the Marine Corps Marathon in hopes of searching the unknown myself. I had a big goal, but faltered late in the race to finish in 2:44. Disappointed, I decided to wait a while before trying another marathon and, though I had qualified for Boston by running faster than the 2:50 standard, I decided to take a pass.

As fate would have it, 17 years went by before I ran my next marathon. Inspired by my 40th birthday, I figured it was time to try again. Running 3:06 and bettering the 3:20 standard for a master, I qualified for Boston a second time. But, I decided the timing was not right.

In the years that followed, I enjoyed a renewed competitive spirit. I set my sights on lowering my masters division PRs and competing with the local hotshots, all the while thinking that I could run a Boston qualifier whenever I was ready. I was wrong.

An old knee injury returned as arthritis and that dimmed my hopes of a future marathon, and with it, my dream of running Boston. And so, when the gun fired this past April, you know what I was thinking.

Regret is a painful thing. It reminds you that you made a mistake. You made a bad choice. You should have taken another path. Fortunately, I have very few-regrets, that is-but, name the city of Boston, and that's what comes to mind. It is kind of funny that a race I never ran has taught me so much. Dick Beardsley saw to my first lesson, and I guess I have myself to thank for the rest.

So what does all this have to do with you? Why not think about it on your next run? Think about searching some unknown territory that just might change your life. Think about moving out of your comfort zone and finding out what you are capable of.

Then, set some priorities and start working to achieve your biggest goals. You are capable of more than you think, and it might just be time to test your potential. Potential, after all, passes away with time. And, most importantly, when your effort opens a new door-be sure to go see what is on the other side.

Dave Griffin writes a bi-weekly running column and offers coaching to high school and adult runners of all levels. Contact Dave by E-mail