J.C. Penney, founder of the retail giant that bears his name, once evaluated one of his young clerks, stating he “wasn’t thorough and wouldn’t have much of a future in the retail business.” The employee? Sam Walton, founder of Wal-Mart.

Despite Penney’s bleak prediction, Sam Walton built the largest retail empire in the world. The opinions of honest, well-intentioned people can sometimes be off the mark. Don’t let misguided judgments keep you from pursuing your dreams.

I love to read about people throughout history who were told they couldn’t do something or wouldn’t amount to anything and then achieved great success. Never give up your dreams just because someone said something negative about you. It doesn’t matter what anyone says; the only thing that matters is what you say and do and think about your ability.

Throughout my life I’ve taken it to heart when someone doubts me or says I can’t really do something. First, I examine myself and evaluate if I think they are right or wrong. And if I think they are wrong, I grow determined to prove them so.

When I thought about running my first marathon at age 56, many of my friends thought I was crazy. I’ve completed 10 marathons to date, and two half-marathons during the last two years.

Naysayers said I couldn’t buy a struggling, tiny, run-down envelope manufacturing company and turn it into anything. Dozens of years later. we’re not just still in business, we’re thriving.

If you have a dream that is reachable and you deeply want something and are willing to work to achieve it, the sky is the limit. History has shown us this many times.

At 15, Michael Jordan didn't make varsity on his high school basketball team.

One of Mark Cuban's first jobs out of college was as a salesman at a computer store. However, he was more interested in cultivating new business than running a cash register. After he failed to open the store one day because he was busy with a potential client, his managers cut him loose. That was the last time he ever worked for someone else.

Lucille Ball was told by the head instructor of the John Murray Anderson Drama School: “Try another profession. Any other.”

John F. Kennedy lost the election to be president of his freshman class at Harvard.

Steven Spielberg’s mediocre grades prevented him from getting accepted to UCLA film school.

Barbara Walters was told to “stay out of television” in 1957 by a prominent producer.

Bob Dylan was booed off the stage at his high school talent show.

Randy Travis was rejected by every major record label, sometimes twice.

Michael Bloomberg was fired as a partner at Salomon Brothers, which eventually became Citigroup, and used his hefty severance check to start Bloomberg Communications, one of the country’s greatest companies.

Julia Child and two collaborators signed a publishing contract in 1953 to produce a book tentatively titled "French Cooking for the American Kitchen." They worked on the book for five years. The publisher rejected the 850-page manuscript. Child and her partners worked for another year, totally revising the manuscript, only to be rejected again. She and her collaborators went back to work, found a new publisher, and in 1961 they published “Mastering the Art of French Cooking,” which has sold more than 1 million copies.

Social media has provided seemingly unlimited opportunities for testing your dreams. Musicians and performers credit YouTube for launching careers. Writers self-publish and promote their works through a variety of platforms. Start-up companies have Facebook connections that broadcast their messages to audiences they could never have imagined reaching.

In short, technology has become a productive partner in dreaming.

The only thing stopping you from living out your dreams is you. It takes determination, motivation, confidence, desire, patience, perseverance and hard work. If you can muster all those elements, you will be unstoppable.

Mackay’s Moral: You must be wide awake to make your dreams come true.

Two friends were walking through a dense jungle. Knowing the dangers, they promised to stick together whatever happened.

Suddenly, a tiger appeared in the bushes. One friend immediately turned and ran, climbing up a tree and leaving his companion behind. He watched as his friend dropped to the ground and played dead.

The tiger approached, sniffed around and leaned down, seemingly whispering something in the man’s ear. It roared once, then stalked away.

Feeling ashamed, the other man climbed back down the tree. “What did the tiger say to you?”

The man looked up. “He said, ‘Never trust a false friend.’”

Some days, you just need to know you have a friend. You need to feel that someone “gets” you and is in your corner. With all the push, pull and tug that can go on in the workplace (and it happens everywhere, folks, even at the good places), you must develop your own support systems -- and friends can be invaluable. Good ones are like rocks; they keep us anchored during our personal storms.

You probably spend most of your waking hours at work, so friendships are natural. Working together can easily turn co-workers into best friends, making jobs more enjoyable and the workplace a home away from home instead of just a way to make a living.

But friendships need to be managed appropriately, just like every other workplace relationship. Follow these simple guidelines so neither your friendships nor your job is at risk.

-- Limit social chatter. Everyone chats a little at work, but don’t let your friendly conversations overshadow your responsibilities. Stay focused on your job.

-- Keep private issues private. When you have problems to discuss, do it over lunch or after work.

-- Avoid gossip. Most of us love to talk about other people, but keep your natural inclination to share rumors about co-workers or managers in check. If colleagues realize you’re gossiping about them, the backlash could be unpleasant.

-- Don’t do each other’s jobs. Pitching in to help a friend in a crunch is admirable, but keep it to a reasonable limit. Your manager is in charge of assignments and responsibilities, not you. Don’t spend so much time helping a friend do his or her job that you neglect your own.

-- Include, don’t exclude. You may prefer the company of your friend, but don’t ignore the rest of your co-workers. Invite other co-workers to lunch, and include them in your conversations so they don’t feel left out. You may even make new friends by expanding your circle at work.

Being there for another person can offer you huge rewards psychologically as well. After all, part of the joy of a good friendship is being there for the other person when life gets rough -- and it does get rough at times for everyone.

Keep in mind the words of Abraham Lincoln -- someone who often needed friends along the difficult path of his presidency: “The better part of one’s life consists of one’s friendships.”

What is a friend? The following description of friendship was spotted on the wall of a doctor’s office by a reader of Bits and Pieces magazine, where it was published some years ago. It was attributed to C. Raymond Beran, about whom little is known.

“Friends are people with whom you care to be yourself. Your soul can be naked with them. They ask you to put on nothing, only to be what you are. They do not want you to be better or worse. When you are with them, you feel like a prisoner feels who has been declared innocent. You do not have to be on your guard. You can say what you think, as long as it is genuinely you.

Friends understand those contradictions in your nature that lead others to misjudge you. With them you breathe freely. You can avow your little vanities and envies and hates and vicious sparks, your meannesses and absurdities, and in opening them up to friends, they are lost, dissolved on the white ocean of their loyalty.

"They understand. You do not have to be careful. You can abuse them, neglect them, tolerate them. Best of all, you can keep still with them. It does not matter. They like you. They understand. You can weep with them, sing with them, laugh with them, pray with them.

"Through it all -- and underneath -- they see, know, and love you.

"What is a friend? Just one, I repeat, with whom you dare to be yourself.”

Mackay’s Moral: The friendships you cultivate will help you grow.

You learn to be book smart in school, but you better not forget that you need to also be street smart. As I like to say, knowledge does not become power until it is used!

I succeeded because I have street smarts that I either developed or picked up throughout my career from some of the world’s smartest and most interesting people.

I have done four previous columns on street-smart ideas, which have generated terrific reader feedback. Here are some more of my favorites.

First idea: Know thy competitor. Walmart founder Sam Walton once walked through a K-Mart store with his CEO, David Glass. David told me this story personally. Sam suddenly stopped in an aisle and said, “How come we’re not doing that?”

Sam Walton spent more time in K-Mart stores than his own stores.

Interesting fact: Both K-Mart and Walmart started in business the same year -- 1962. Walmart’s sales last year were $482 billion, while K-Mart sales were a paltry $10 billion.

Next idea: Channel your inner child. We start out as pretty creative beings -- children let their imaginations take them to places they’ve never seen and do things that seem impossible. We encourage this as fun and playtime, but we should celebrate it as the potential for great discovery and accomplishment.

Here's a quote often attributed to Pablo Picasso, arguably one of the most creative artists in history: "Every child is an artist; the problem is staying an artist when you grow up." Or maybe you can be inspired by another notable thinker, Dr. Seuss (aka Theodore Geisel): “Think left and think right and think low and think high. Oh, the thinks you can think up if only you try.”

Next idea: The most important term in any contract isn’t in the contract. It’s dealing with people who are honest. The second most important term is including the right to inspect all their books and records, including tax records, correspondence and so on, pertaining to the agreement. Once that clause is in there, people with a tendency to get cute usually don’t.

Next idea: Everything is negotiable. Everything has a price. A deal can always be made when the parties see it to their own benefit. Nine out of 10 lawsuits are settled on the courthouse steps before proceeding to trial. Even the most bitter of adversaries will sit down at the same table when they can be shown there is a greater advantage to themselves in negotiating than in fighting. The worst settlement is usually better than the best lawsuit.

Next idea: The given reason is seldom the real reason. You must find out the real reason to be successful. In sales, you are asking for the order your entire career. When a person says no, they seldom tell you the real reason.

For example, way over half the time, the prospective buyer will tell you that your price is too high, there isn’t enough difference in price to switch, they are concerned about your delivery schedule, they have a long-standing relationship with their current supplier -- a myriad of reasons.

It’s your job to discover the real reason. Then and only then can you can work to overcome their objections.

Next idea: Paint your wagon. Did you ever notice how many people happen to work in office buildings more than one story in height? And how many of these same people look out the window off and on during the day? Why not paint your company name and logo on the top of your delivery vehicles or trucks? It’s the easiest, least expensive and most neglected form of advertising.

Next idea: Call on people on their birthdays. I always make it a point to visit my customers on their birthdays. If you can’t get to them personally, call or email them. Send them a humorous but tasteful birthday card. Stress this tip with your salesforce.

You won’t believe how much business we write up on our customers’ birthdays. They are in a good mood. Bring them a creative gift. You are not buying their business, you are building a relationship.

I once figured out that I make approximately 300 phone calls a year to my customers and friends on their birthdays. I always try to put a smile on their face by singing "Happy Birthday" in a humorous voice.

Mackay’s Moral: Using your street smarts will put you on the road to success.