By Adam Toren

There's something about quotes that we all find irresistible. Maybe it's that they tend to come from ordinary people who have gone on to do extraordinary things in their lives. Perhaps it's the vast array of professions, circumstances, niches and places they come from that fascinate us. Or it could be that by reading their words we tap into something we feel is possible for ourselves as well. Whatever it is, there's nothing like a great quote to get your revved up.

Here are 21 inspiring quotes that will get you hyped up and keep you motived as an entrepreneur.

1. I can accept failure. Everyone fails at something. But I cannot accept not trying. -- Michael Jordan

Just like the great Yoda once said, "Do, or do not. There is no try." You may fail at some things in your life, but you'll fail at life if you don't continually try and do new things.

2. Be patient with yourself. Self-growth is tender, it's holy ground. There's no greater investment. -- Stephen Covey

It is common to be in a rush to reach the destination called success. There's success with a romantic partner, which usually means marriage or success with a business, which usually means an IPO or exit strategy. Success is often measured by the destination. However, if you can learn to be patient, and continually improve yourself while enjoying the journey, the trip to every success will be as pleasant as the destination. Improving yourself is always worth the investment.

3. In every success story, you will find someone who has made a courageous decision. -- Peter F. Drucker

Success takes a spirit of adventure and an aptitude for bravery. It isn't that the brave don't have fears, it's that they chose to move forward anyway.

4. If you can dream it, you can do it. -- Walt Disney

Every great success starts with a big vision. What's yours?

5. We must train from the inside out. Using our strengths to attack and nullify any weaknesses. It's not about denying a weakness may exist but about denying its right to persist. -- Vince McConnell

Investing in yourself means a continual assessment of self-improvement, and that process weeds out our weaknesses. 

It's not about perfection, but if we focus on overcoming our inner obstacles to success, we can conquer the world within and then the world outside.

6. All of the great leaders have had one characteristic in common: it was the willingness to confront unequivocally the major anxiety of their people in their time. This, and not much else, is the essence of leadership. -- John Kenneth Galbraith

Leadership, like entrepreneurship, takes courage and the ability to remain comfortable in times of discomfort. The more you can cultivate being at ease during times of challenge, the greater your life and your leadership will be.

7. My best advice to entrepreneurs is this: Forget about making mistakes, just do it. -- Ajaero Tony Martins

Don't focus on the failures. Focus on the journey toward results. It's better to do something and fail than to not try anything at all.

8. Achievement seems to be connected with action. Successful men and women keep moving. They make mistakes but they don't quit. -- Conrad Hilton

There is action required for all success. Success never means a lack of failures along the path, but always means your continue down the path even after stumbling or falling. It's the old proverb that you might fall down nine times, but to be successful you must stand up 10 times.

9. Ambition is the steam that drives men forward on the road to success. Only the engine under full steam can make the grade. -- Maxi Foreman

You need a big vision and some lofty ambition to change the world, even if the world you aspire to change is only your own local community. Dream big and take action toward those ambitions.

10. Continuous learning is the minimum requirement for success in any field. -- Dennis Waitley

Never stop learning. If you aren't learning, then you're quickly becoming obsolete. Surround yourself with smart people who will always challenge you with new ideas, new technologies and show you new ways things could be done.

11. Everyone who achieves success in a great venture solved each problem as they came to it. They helped themselves and they were helped through powers known and unknown to them at the time they set out on their voyage. They kept going regardless of the obstacles they met. -- W. Clement Stone

Failure is a theme with great quotes and great leaders because it's so personal and also so universal. Rise up from challenges and move forward after your failures and you will meet with success.

12. Experience taught me a few things. One is to listen to your gut no matter how good something sounds on paper. 

The second is that you are generally better off sticking with what you know and the third is that sometimes, your best investments are the ones you don't make. -- Donald Trump

You should trust your inner voice and go with your gut, even when it's telling you not to do something — perhaps especially when it's telling your not to do something. Learning to trust your own judgment will take you far.

13. Failure isn't failure unless you don't learn from it. -- Dr. Ronald Niednagel

Yes, you need to move forward after failure, but perhaps the most important thing about failure is the lesson you learn from it. What can you change in the future to not repeat the mistakes of your past? So long as you change a different variable every time you attack the same problem, you'll find a way to overcome and reach a solution.

14. Enthusiasm is the sparkle in your eyes, the swing in your gait, the grip of your hand and the irresistible surge of will and energy to execute your ideas. -- Henry Ford

When you love what you do, you have the passion you'll need to fuel the often intense road of entrepreneurship. Keep that passion alive.

15. Desire is the key to motivation, but it's determination and commitment to an unrelenting pursuit of your goal — a commitment to excellence — that will enable you to attain the success you seek. -- Mario Andretti

Desire, like passion, fuels you forward during times of challenge to achieve your success. Every entrepreneur should have a healthy dose of desire to reach their big vision if they want to eventually arrive at success.

16. The secret of joy in work is contained in one word: excellence. To know how to do something well is to enjoy it. -- Pearl Buck

You should strive for excellence in all you do. It's a hallmark of innovation and integrity to reach excellence in your work.

17. If you hear a voice within you saying "you are not a painter" then by all means paint and that voice will be silenced. -- Vincent Van Gogh

This is a great quote because it emphasizes the importance of action. If you don't know how to paint, the best way — really the only way — to learn is to pick up a paintbrush. You don't need to be an entrepreneur to get started with your first endeavor. You need to get started with your first endeavor to be an entrepreneur.

18. You are to set your own value, communicate that value to the world, and then not settle for less. Sound daunting? That's just because it takes you out of your comfort zone. You have got to stop being an obstacle on your own path to wealth and security and happiness. You must understand that valuing yourself is well within your control. -- Suze Orman

One thing that is easy to do when you're starting as an entrepreneur is to put yourself on sale. When you don't have an understanding of your own value and worth, don't expect others to either. This isn't so much a dollar sum as it is a belief in yourself, in your innate ability to succeed and the drive to move your way forward to success. Know your worth and then act on it.

19. The greatest discovery of my generation is that people can alter their lives by altering their attitudes. -- William James

The greatest single factor you can consciously decide to implement right now is your attitude. Be outrageously, contagiously optimistic and resilient. Decide now that your attitude is going to be amazing to be around for others.

20. Failure is just a resting place. It is an opportunity to begin again more intelligently. -- Henry Ford

Learn from your mistakes and take each failure as an opportunity to begin again, but with a new knowledge to apply to the steps ahead.

21. The entrepreneur is essentially a visualizer and actualizer. He can visualize something, and when he visualizes it he sees exactly how to make it happen. -- Robert L. Schwartz

When you have a big vision, and you combine that perspective with action, there's nothing you can't do.