Entrepreneurship can be a tough path--and a long, grueling one. Littered with false starts and failures, it tends to trigger a rollercoaster of emotions: excitement,  despair, determination, and confusion, to name a few.

Because it's so rarely linear (just try to find a successful entrepreneur who hasn't fallen flat on his or her face at some point), the thing is requires more than anything is stamina: You've got to be able to keep going even when you don't feel like it, and draw on deep reserves of energy to go to the distance.

Need a little help filling that well? Here's some inspiration from those who've come before, to help you get to where you want to be:

1. "Don't be intimidated by what you don't know. That can be your greatest strength and ensure that you do things differently from everyone else." - Sara Blakely

2. "A person who never made a mistake never tried anything new." - Albert Einstein

3. "The greater danger for most of us lies not in setting our aim too high and falling short, but in setting our aim too low and achieving our mark." - Michelangelo

4. "Don't let the noise of others' opinions drown out your own inner voice." - Steve Jobs

5. "Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great." - Mark Twain

6. "Age is something that doesn't matter, unless you are a cheese." - Billie Burke

7. "Find the smartest people you can and surround yourself with them." - Marissa Meyer

8. "One of the most important things I have learned is that businesses don't fail, entrepreneurs give up. Now sometimes, giving up is the right decision. But usually you just need to dig in and figure out how to make things better. Remember: Every day is a new opportunity to get up and do it better than yesterday!" - Adda Birnir

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

10. "The secret of getting ahead is getting started." - Sally Berger

11. "Achievement seems to be connected with action. Successful men and women keep moving. They make mistakes but they don't quit." - Conrad Hilton (founder of Hilton Hotels)

12. "There is only one way to avoid criticism: Do nothing, say nothing, and be nothing." - Aristotle

13. "Take criticism seriously, but not personally." - Hillary Clinton

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

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

16. "If you obey all the rules, you miss all the fun." - Katharine Hepburn

17. "It's not about money or connections. It's the willingness to outwork and outlearn everyone when it comes to your business." - Mark Cuban

18. "If Plan A doesn't work, the alphabet has 25 more letters." - Claire Cook

19. "The most effective way to do it, is to do it." - Amelia Earhart

20. "Strive for authenticity over perfection." - Sheryl Sandberg

21. "What good is an idea if it remains an idea? Try. Experiment. Iterate. Fail. Try again. Change the world." - Simon Sinek

22. "Stop wearing your wishbone where your backbone ought to be." - Elizabeth Gilbert

23. "I stand up on my desk to remind myself that we must constantly look at things in a different way." - Robin Williams 

24. "I hated every minute of training, but I said, 'Don't quit. Suffer now and live the rest of your life as a champion.'" - Muhammad Ali

25. "If you're going through hell, keep going." - Winston Churchill

26. "The question isn't who is going to let me; it's who is going to stop me." - Ayn Rand

27. "Don't look at your feet to see if you are doing it right. Just dance." - Anne Lamott

28. "Don't compromise yourself. You are all you've got." - Janis Joplin

29. "There is only one success: to be able to spend your life in your own way." - Christopher Morley

30. "If you think you are too small to make a difference, try sleeping in a room with a mosquito." - Lisa Lieberman-Wang

31. "It's more fun to be a pirate than to join the navy." - Steve Jobs

32. "Remember why you started." - Anonymous

33. "Screw it, let's do it." - Richard Branson