Although my days of running marathons are just pleasant memories, I still get the itch this time of year, when the Twin Cities and Chicago marathons are held.

I have 10 marathons under my belt, including four New York races and one in Boston. When running a grueling race with thousands of people, for most it doesn't matter where in the pack you finish. What matters is simply that you finish. It's all about persistence.

Even the elite runners - those who finish the 26.2-mile trek in a little over two hours - have to convince themselves to take the next stride. Imagine how a runner who is still at it after four or five hours feels! Then think about the rush that comes when the finish line is in sight.

The difference between those who finish and those who give up lies in the old axiom that successful people do those things that unsuccessful people don't like to do. Successful people have the determination, the will, the focus and the drive to complete the tough jobs - like running a marathon. Or launching a business.

Gerald Levin must have felt he was running a marathon when he took on the challenge of making something out of a subscription TV service called Home Box Office in the early '70s. He set up a satellite distribution system at a time when he was suing the federal regulators who approved cable TV licenses.

Levin believed in his product and pushed on. He heavily promoted HBO to TV watchers at a time when few homes had cable TV. Now HBO is a household name, and Levin went on to become chairman of Time Warner Inc.

You may recall the story about when I was starting out, and asked a colleague I respected how many calls he would make on a prospect before giving up. He told me, "It depends on which one of us dies first."

Keeping your eye on the prize is usually easier said than done. It's easy to get overwhelmed by the demands of a long-term project. Here are some strategies for staying motivated:

n Focus on what you can accomplish rather than obstacles. Direct your energy toward achieving a goal, and tackle the problems with an emphasis on edging closer to a successful result.

n When you identify a roadblock, develop a realistic plan to overcome it.

n Refuse to give up. Alter your course if necessary, but concentrate on the desired conclusion.

n Work with your colleagues or employees to make it easy for them to say yes to your requests. Never ask them to do something that you wouldn't do yourself. Provide options so they can contribute to the best of their abilities.

n Be assertive without being aggressive. Set the direction, and take responsibility for results.

Persistence and determination are what keep us hammering away. I don't know any entrepreneurs who have achieved any level of success without those two traits. When you have a dream that you can't let go of, trust your instincts and pursue it.

One of my favorite stories is about a dreamer whose name was Henry Comstock. Henry was a miner of precious metals whose story took place in the American West in the mid-1800s.

Henry found a mine, staked his claim and dug until he found his treasure. He unearthed a little bit of ore, but he knew there was more to be found in that mine. So he picked and scratched, always convinced that somewhere there had to be the mother lode. He was determined to find it. He was really going to make it big.

The days turned to weeks, the weeks to months, the months to years and finally he gave up in 1859, when someone offered him $11,000 for his claim. In those days, that was a lot of money. Henry Comstock looked at the buyer and said: "You've made yourself a deal. You've got yourself a mine."

The person who bought it dug a little deeper - just a few feet deeper - and the mother lode was found. Within a short time, the Comstock mine produced ore worth $340 million!

Dreams take work, they take practice, they take patience, and sometimes they require you to dig deeper.

Mackay's Moral: Instead of giving myself reasons why I can't, I give myself reasons why I can.

Harvey Mackay is the author of the New York Times best-seller "Swim With the Sharks Without Being Eaten Alive." He can be reached through his website, www.harveymackay.com, by emailing [email protected] or by writing him at MackayMitchell Envelope Co., 2100 Elm St. SE, Minneapolis, MN 55414.