There's an epidemic sweeping the country, and the cure is just outside the window. Spring fever is infecting folks from coast to coast, following the winter that wouldn't end with its record snowfalls and biting temperatures and the dreaded polar vortex.

And what would spring be without spring cleaning? We sweep out the cobwebs in the corners and clean out the garage. Pack up the boots and stow the winter blahs. It's time for a fresh start!

Why confine that spring cleaning to the house? It's the season for fresh thoughts and new starts. Forgotten all your New Year's resolutions? Ready to actually turn over a new leaf? Then spring into action! A change of season is a perfect time for a change of attitude.

Start with the clutter around you. It's hard to think straight when you are surrounded by a mess. Clear off your desk. Go through your email and messages and deal with any outstanding business. Put files in order. Get organized and do it in a way that you can maintain on a daily basis. Once your environment is manageable, you can move on to the next step.

Now you are ready to tackle the tough stuff: your mindset. Set aside some time -- and it may take some time -- to think about what you could do to make your situation better.

Maybe you have a bad habit that needs work. Giving up a vice is never easy, but you need to keep it in perspective. Is it holding you back from being healthy or happy? Then any amount of effort is worth it. Aim for one thing at a time if you want to improve your chance of succeeding.

Get outdoors and breathe in fresh air. Spring is a great time to get into a routine of walking, running, biking, playing golf or tennis, or anything that gets you moving. Exercise is good not only for the body; it's also great for your mind. It improves concentration and creativity. And the change of scenery has advantages too -- nothing like a crisp, sunny day to brighten your outlook.

Spring is a great time to fix what needs fixing in anticipation for the coming season. What is your biggest fear? Think about how it messes with your mind. Write it down and then consider what you can do to conquer it. It isn't necessary to climb Mount Everest to get over your fear of heights. And it's helpful to remember that more than 90 percent of the things we worry about aren't worth the concern because they never happen.

Maybe you are thinking about a job change or a move. That can't happen without some research and planning. Spring represents hope for new beginnings -- perhaps this spring is a good time to get the ball rolling. Think about the steps you need to take. Do your homework and make a punch list. You may discover that changing your situation is not as difficult or as far out of reach as you imagined.

Freshen up your brain. Perhaps there are some classes that would help you in your career, or give you the satisfaction of learning something new and interesting. It's like a fresh coat of paint for your attitude. Spruce it up and see what else you decide to improve.

Are you familiar with the Zeigarnik effect? It is named after a Russian psychiatrist who discovered that a waiter could remember orders he had not served yet more easily than orders that were served. Further study showed that people are 90 percent more likely to remember tasks that are undone than those they completed. That makes sense to a degree, but it also causes tremendous stress rather than pride of accomplishment. There is always work to be done, but stop and smell the roses -- or the crocuses and daffodils -- occasionally! And seriously, what do you think you would do if suddenly all your work were done?

Spring is also a time to turn your clock forward. Start thinking about how you can control your time better, rather than always reacting to others' demands. Take charge of your schedule! If you can't bring yourself to say "no," learn how to say "later" or "I'll think about it." Your time is valuable -- so valuable, you can't put a price on it. And once it's gone, it's like snow melting when winter is over.

Mackay's Moral: The best cure for spring fever is a sunny outlook.

Like so many others in business, I have accumulated my share of enemies over the course of a lifetime. It's nothing to be ashamed of. "Forgive thy enemies" is difficult advice for many of us 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 our grudges for many, 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 home in San Diego.

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 truly priceless.

After dinner, Price took Bernie to a room in his house filled with papers stacked five to six feet high and no furniture. They were all depositions from a lawsuit Sol had been involved with. He told Bernie that the lawsuit 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 when Bernie woke up, he said he "really woke up. I called the attorneys and said, 'You're off the case. End the litigation. I'm going on with my life.'"

Just where did Bernie go? One year later in 1979, he and Arthur Blank launched The Home Depot, which became the fastest growing retailer in U.S. history.

You will never get ahead of anyone as long as you are trying to get even with him because in order to get even with him, you have to stoop to his level. If you didn't like their tactics, why would you want to emulate them?

I am not in any way advocating being a patsy for another's bad behavior. But you must weigh whether bringing another person down will lift you up. Take the high road whenever you can -- it's usually not too crowded.

You must also consider what exacting revenge does to your physical and mental health. Will it really make you feel better? Consider the words of Martin Luther King Jr., an advocate for forgiveness and peace: "The old law about 'an eye for an eye' leaves everybody blind."

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

I hate to lose. And that is how Nick Bollettieri became my friend.

When I was in my early 20s, I gave up my dreams of becoming a professional golfer. Actually, I am a pretty good golfer, but I knew that I wasn't going to be the next Arnold Palmer. Eventually I decided to seriously pursue the game of tennis. And I wanted to be really, really good.

I headed to Dorado Beach, Puerto Rico, in the early 1970s for some lessons with Nick. From the moment I gripped my racquet, I knew the ball was in my court. He worked me harder than I ever thought possible. As a coach, Nick is feisty, combative and one of the greatest motivators I've ever met. He always delivers more than he promises.

For those not fortunate enough to have worked with Nick, I am pleased to share news of his terrific new autobiography, "Bollettieri: Changing the Game." You needn't be a tennis lover to benefit from his story. Nick is a master motivator and one of the most competitive people you'll ever meet. He has dominated the field of sports training for five decades and is still going strong.

What makes an icon? What makes a one-in-a-million coach? What fuels his intensely competitive spirit? And what on earth keeps this 81-year-old so invulnerable to the challenges of a few decades?

The answers to all those questions start and end with one single trait: He has always been determined to be the best he could be. Nick could have entered any profession and he would have been a superstar.

The clinics he has conducted around the world are legendary. People of all ages and skill levels flock to his academies, now part of IMG Academy. Nick has coached and developed 10 No. 1-ranked players: Andre Agassi, Jim Courier, Boris Becker, Monica Seles, Serena and Venus Williams, Martina Hingis, Maria Sharapova, Marcelo Rios and Jelena Jankovic.

Nick does double duty as a coach, both for the player and the parents of his prodigies. He defines the complex relationship: "The player can't be successful without player/parents/coach understanding each other's roles."

He founded the Nick Bollettieri Tennis Academy in 1978, the first full-time tennis boarding school to combine intense on-court training with a custom-designed academic curriculum.

Teaching such a diverse group of students at so many skill levels requires a multi-dimensional approach. His secret? Find the idiosyncrasies of each individual and then work from there. His methods have been the secret to his success for 55 years of teaching.

Nick's total package blends technical and strategic on-court training with specialized performance physical training and mental conditioning. His goal is to go beyond training just the physical aspects of the game. He aims to prepare his students for a successful life off the court as well. His college major in philosophy creeps into lessons and long-term thinking.

Nick was a pioneer in the field, which means he took the arrows that go along with the territory. His vision wasn't shared by his peers (if he actually has any), and the critics didn't hold back. Then they saw his results. The noise eventually died down. As Nick says, "You don't coach skills. You coach people."

Nick demands the best from his students because he only gives them his best. He doesn't settle for average from anyone. Nick produces champions because he is a champion himself, and his students are the big winners.

He has established fabulous inner city youth programs for minority youth. Nick understands that they don't pay off on effort; they pay off on results. In my own hometown of Minneapolis alone, Inner City Tennis touches the lives of about 5,000 kids every year, as well as the 100-plus volunteer senior citizens who, as coach/mentor/tutors, build an intergenerational rapport with these children. The program focuses on the development of these young people in specific characteristics such as responsibility, respect, teamwork, enthusiasm, integrity, perseverance and service.

By the way, it is the only board that Nick has ever agreed to serve on, even though he has been asked to join hundreds.

Nick's story is well worth the read. Just as with his coaching, he doesn't hold back.

Mackay's Moral: Nick Bollettieri is a game changer -- he serves up aces from which we all can learn.