"When my legs hurt, I say: 'Shut up, legs!'" I love this quote from German cyclist Jens Voigt. He would yell this when the pain of long mountain stages in major races like the Tour de France would start to seep in. And he would keep pedaling.

It reminds me a lot of what it takes to be an entrepreneur -- the willingness to keep going when you are stretched and tiring.

Building a successful business that is lasting is a long journey. That is why you need to keep pushing. And the inspiration to do so often comes from remembering why you started in the first place. So, where do you find your inspiration?

I recently posted about words that inspire on LinkedIn, and a few folks chimed in with their favorite movie-inspired quotes. But movies are not the only place to find company-building inspiration. Some of the best lessons come from real-life leaders and champions -- those who have defeated the odds to find success.

Here are 13 quotes for aspiring entrepreneurs -- broken out by the focus areas that I believe are most important to successful founders:


"Risk comes from not knowing what you're doing." -- Warren Buffett, chairman and CEO of Berkshire Hathaway  

"We asked ourselves what we wanted this company to stand for. We didn't want to just sell shoes. I wasn't even into shoes -- but I was passionate about customer service." -- Tony Hsieh, CEO of Zappos

"You cannot deliver value unless you anchor the company's values. Values make an unsinkable ship." -- Indra Nooyi, CEO of PepsiCo


"Motivation comes from working on things we care about. It also comes from working with people we care about." -- Sheryl Sandberg, COO of Facebook

"If you want to create a great product, just focus on one person. Make that one person have the most amazing experience ever." -- Brian Chesky, CEO of Airbnb  

"Your most unhappy customers are your greatest source of learning." -- Bill Gates, business magnate and principal founder of Microsoft  


"That's been one of my mantras -- focus and simplicity. Simple can be harder than complex: you have to work hard to get your thinking clean to make it simple. But it's worth it in the end because once you get there, you can move mountains." -- Steve Jobs, entrepreneur and co-founder of Apple

"I don't focus on what I'm up against. I focus on my goals and I try to ignore the rest." -- Venus Williams, championship tennis player


"No big challenge has ever been solved, and no lasting improvement has ever been achieved, unless people dare to try something different. Dare to think different." -- Tim Cook, CEO of Apple

"Have a healthy disregard for the impossible." -- Larry Page, co-founder of Google and CEO of Alphabet


"If you absolutely can't tolerate critics, then don't do anything new or interesting." -- Jeff Bezos, CEO of Amazon

"Many of life's failures are people who did not realize how close they were to success when they gave up." -- Thomas Edison, inventor  

"If you're following your calling, the fatigue will be easier to bear, the disappointments will be fuel, the highs will be like nothing you've ever felt." -- Phil Knight, co-founder of Nike

Moments of trial are inevitable when you are starting a business. And sometimes the best encouragement comes from looking at what you have accomplished and what you still want to do. It also comes from watching and learning from others.  

All of these leaders remind me that the most important thing you can do each day is to stay in the race. Yes, even when it feels grueling. And even when you have to shout, "Shut up, legs!" to keep pushing ahead.

What quotes would you add to the list?