Students in a philosophy class were anxiously awaiting the start of their final exam. The professor had warned them that it would be one of the most challenging tests they would ever take.

The teacher wrote one question on the board and said, "This is your exam. You have one hour to complete it."

One student scribbled something quickly and turned in his exam, casually walking out of the room. The other students continued to write furiously as they looked on in disbelief.

The professor chuckled when he looked at the exam and wrote on it "Great job! 100 percent."

The question: "What is courage?"

The student's answer: "This is."

Every day, examples of courage are all around us. Courageous folks may not be winning awards, getting their names in the news or resting on their laurels. They are running businesses and nonprofit organizations, working in the trenches to go the extra mile for customers and volunteering for causes in their communities. They face challenges and discouragements that threaten their financial and emotional futures. Yet they persevere.

Maxwell Maltz, the author of "Psycho-Cybernetics," offered this explanation: "We must have courage to bet on our ideas, to take the calculated risk and to act. Everyday living requires courage if life is to be effective and bring happiness."

Courage is one of the themes of the recently released movie "Joy," the story of Joy Mangano, who invented the Miracle Mop and Huggable Hangers. She holds more than 100 patents for her inventions. She used her life savings and borrowed from family and friends to create the Miracle Mop. It took two years of personally selling the mop in supermarkets and working out of her bedroom before she achieved big-league success. Her kids filled the orders.

"Whenever you start something new, in business or life, doubt comes easy but courage takes work," Joy wrote on a Home Shopping Network blog.

"You must be brave and you must be strong to have the courage to keep going when you do experience the struggles of being an entrepreneur," she added. "I think a large part of my success came from my drive to bring something bigger into the world and to show my children that they could also accomplish their dreams, no matter the obstacles."

More than 25 years ago, I wrote my first book, "Swim With the Sharks Without Being Eaten Alive." The book stayed on the New York Times best-seller list for over a year. Why? Because it inspired people to have the courage to take risks and trust their instincts. The advice I offered then is just as relevant today.

Was I ever afraid that I would fail? Yes and no. Yes, because I didn't want to be embarrassed or disappoint others. No, because I had the courage to be confident in my ability to survive failure and celebrate success.

Dr. Charles Garfield, author of "Peak Performance," tells the story of a wealthy man who bought a ranch in Arizona and invited some of his closest associates to see it. After a tour of the estate, he took everyone to the house, at the back of which was a swimming pool filled with alligators.

The rich owner said: "I value courage more than anything else. Courage is what made me a billionaire. In fact, I think that courage is such a powerful virtue that if anybody is courageous enough to jump into that pool, swim through those alligators and make it to the other side, I'll give them anything they want -- my house, my land, my money."

Everyone laughed and started walking into a house when a loud splash was heard. The crowd saw a man swimming for his life across the pool, as the alligators pursued him. After a heart-stopping interval, the man made it to the other side and exited the pool without injury.

The rich host said, "You are indeed a man of courage. What do you want? You can have anything."

The swimmer, out of breath, said, "I just want to know one thing -- who pushed me into that pool?"

Mackay's Moral: It's advantageous to be courageous.

Two old friends met at a local social gathering and one was struck with how sad and depressed the other was.

"You look like your world is about to end," said Jack.

With a sad face, Joe replied, "You don't know the half of it. Three weeks ago, an aunt of mine died and left me $100,000."

"That's terrific!" Jack said.

Scarcely pausing, Joe added, "Two weeks ago, this cousin I never heard of died, and I was his closest relative, so the lawyer said I'd inherited $95,000, all tax free."

"So why is that bad?"

"Then, last week, a grandfather I haven't spoken to in 10 years passed away, and he left me almost half a million dollars!"

"So what's your problem?"

"This week: Nothing!"

The moral of the above anecdote is that you just can't please everyone.

I'm an eternal optimist. Where there is an optimist, there is a way. Success requires irrepressible optimism.

Just ask corporate giant Michael Eisner, former Walt Disney Company CEO, how he became so successful, and in a heartbeat, he'll say optimism. In his book, "Work in Progress," Eisner says he has been upbeat for as far back as he can remember. As a kid, he went to New York Giants football games with a firm belief that his team would win. In those days the squad was mediocre at best, and by the fourth quarter the Giants would usually be down by four or five touchdowns. When his friends would want to leave early to beat the crowds out of the stadium, Eisner insisted on staying, sure that the team could mount a last-minute comeback. Even though the Giants invariably lost, Eisner would attend every game certain the Giants would win. It was this kind of irrepressible optimism that propelled Eisner into the highest ranks of some of the most successful companies in the world.

M.J. Ryan, life coach and author of "The Happiness Makeover," says that it's possible for just about anyone to revamp their thinking. "Training your brain is like training a puppy," she says. "It wanders everywhere, but you need to keep bringing it back to the upside."

But being too optimistic has its problems, say researchers at Duke University's Fuqua School of Business. The study, originally published in the Journal of Financial Economics, discovered that people who are generally optimistic usually display prudent financial behaviors, but people with too much optimism tend to have short planning horizons and often do things that are considered unwise.

The researchers asked survey participants how long they expected to live. Anyone who reported expecting to live longer than the statistical life expectancies was categorized as an optimist. Those who thought they would live 20 years longer than statistical life expectancies were considered extreme optimists.

The study found that optimists work longer hours, save more money, are more likely to pay their credit card balances on time, believe their income will grow over the next five years and plan to retire later (or not at all). But extreme optimists work significantly fewer hours, save less money and are less likely to pay off their credit card balances on a regular basis.

You have the power to control your outlook. Just remember these three things.

-- Tell yourself you can change. Consider how you've changed throughout your life emotionally. Don't assume you can't evolve further.

-- Use positive language. Banish words and phrases like "impossible" and "I can't" from your vocabulary. Replace them with words that emphasize strength and success: "challenging" and "I must."

-- Let go of mistakes. You're bound to fail at some things; don't obsess over them. Learn what you can and move on.

Mackay's Moral: Optimists are people who make the best of it when they get the worst of it.

The other day I was with a friend who was telling me how stressed he was. He felt that everyone wanted a piece of him and he was spread too thin. He didn't want to disappoint people, especially family. I told him he needed to learn how to say no.

Like most of us, he had no idea how to gracefully but firmly decline requests.

Why is it so hard? It's just a tiny two-letter word that is tremendously liberating. So why do we feel so guilty saying no? Do you recognize these descriptions paraphrased from Michelle Tullier's "The Complete Idiot's Guide to Overcoming Procrastination":

Some people have a great sense of duty and obligation. They feel like they have to say yes to almost anything they are asked to do -- and end up feeling resentful and burned out. Others just want everyone to like them. They're afraid if they say no, they might cause the person making the request to reject them. Some are afraid they'll miss out on a big opportunity if they say no. Then there are those who feel flattered when they are asked to do something. Some people hate confrontation so much they will do almost anything to avoid it. They are called pushovers.

Inevitably, someone will ask you to do something you don't have the time or ability to do. In an effort to please everyone, you may say yes. While your intentions may be honorable, the result may be falling short of completing any obligation well. So everyone might be better served if you just say no.

You probably can't turn down orders from your boss, but you can take more control of your time by not letting co-workers bury you with requests. Help when you can, but remind people politely that you've got to stick to priorities. Don't let extraneous tasks overtake your calendar.

And while it's great to be needed, don't try too hard to become your organization's "go-to" person whenever something needs to be done. You won't get ahead if you're too busy to do good work. Before you get stretched too far, consider how to say "no" without alienating your boss and your co-workers:

-- Explore the assignment. Find out why you're being asked to take on this job. Are you really the only person who can do it? Is it really urgent? The more you know, the more negotiating room you have.

-- Clarify your own priorities. Explain what else is on your plate and why it's important. Other people may not realize what your priorities really are, and won't press the question once they understand the scope of your other responsibilities.

-- Adjust your workflow. If your boss wants you to do something extra, use the request as an opportunity to shift your other projects: "I can do that, but my report on the Jones Project will be late -- is that OK?" This shows you're thinking about priorities, and may make your boss rethink his assumptions about your workload.

-- Don't say anything when you're put on the spot. Take some time to think it over.

-- Be polite, but firm. Don't build false hope about what you can do. Don't say, "I'll try." You'll just worry about squeezing the request into your schedule or how you're going to say in the end that you didn't get it done.

Let me just add, from a management perspective, I love when people are willing to take on extra tasks when necessary. I do not love when their work is substandard or their usual responsibilities suffer, just to prove how many balls they could juggle at one time. That tells me that they are weak on time management.

Saying no is not the same as saying never. It's an acknowledgement that you respect yourself as well as the person doing the asking. Believe me, it won't stop him or her from asking again!

Mackay's Moral: Know when to say no.