Like so many others in business, I have accumulated my share of enemies. It's nothing to be ashamed of. "Forgive thy enemies" is difficult advice to follow. After all, if we feel people have harmed us, we tend to want to get back at them. As a result, we can carry grudges for many years.

And, of course, it is totally counterproductive. I once fired an employee who then went into competition with me and began using what I felt were unfair business tactics. The psychic energy and accumulated bitterness that went into my thoughts of revenge consumed me for the better part of five years.

It was more than a waste of time, because whenever I thought about it, I grew vindictive and sour, and those attitudes spilled over into everything I touched. As a result, I lost more than the object of my revenge. Something had to give. And that something was me.

If you can't take the best advice and forgive your enemies, then take the second-best course and forget them. The only way you can achieve true revenge is to not let your enemies cause you to self-destruct.

I learned a similar story from Bernie Marcus when I was interviewing 29 people for my book "We Got Fired! … And It's the Best Thing That Ever Happened to Us." In 1978, Bernie was fired as the CEO of Handy Dan Home Improvement Center chain by Sanford C. "Sandy" Sigoloff, who ran the parent corporation, Daylin. Bernie was 49 years old and had never been fired before. He called it "the low point in his life."

Bernie was wounded and aching. His first and only thoughts were about getting even.

"It's interesting when you have a low like this, you reach one point where you have a chance of coming out or not coming out," he said. "If you come out, you're better than you ever were. If you don't come out, you become what they commonly refer to as a 'loser.' If you come out, it's usually because of the influence someone has on you."

Fortunately for Bernie, that influence was Sol Price, founder of Price Club, which has since become part of Costco. Price phoned Bernie and invited him to dinner at his San Diego home.

Bernie got right to the point: "My contract with Daylin was worth a million dollars. Sandy broke the contract. I want to get back at him. Right now I'm suing Sandy for that million."

To wage the suit, Bernie said, he was eating up cash like it was going out of style. Price understood, and the strategy he offered was priceless.

After dinner, Price took Bernie to a room filled with papers stacked 6 feet high. They were all depositions from a lawsuit Sol had been involved with. He told Bernie that the suit consumed much of his energy and strength for three years of his life.

Price told Bernie: "Why are you spending your young life suing somebody? Why don't you just forget about it and go on and live your life? Otherwise, you're going to end up with a room like this."

The next morning, Bernie called his attorneys and said, 'End the litigation. I'm going on with my life.' "

One year later in 1979, Bernie and Arthur Blank launched the Home Depot, which became the fastest-growing retailer in U.S. history.

Mackay's Moral: Revenge may seem sweet, but it makes for a sour disposition.

Mackay is a Minneapolis businessman. Contact him at 612-378-6202 or harvey@mackay.com.