The life of an entrepreneur is not easy. The journey to the top is slow and requires persistent hard work day in and day out. Even then, success is not guaranteed and there is a very good chance for an entrepreneur to be left without a job or income after years of relentless effort. Given these hardships, what makes entrepreneurs stick to their passion?

I talked to over a hundred entrepreneurs for my book, “How We Did It : 100 entrepreneurs share the story of their struggles and life experiences” and got the opportunity to listen to these incredible people firsthand. A popular answer from all these entrepreneurs was that they simply didn't know any better. However, these entrepreneurs had incredible stories and experiences to share from their startup journey. Here are a few of them.

1. Sam Tarantino, the Founder & CEO of Grooveshark

"The single greatest lesson in life I’ve learned is that anything you have can be taken from you. Who you are and what you stand for cannot. That is eternal and the root of happiness. Money, fame, status, power, people, things, all can be lost. Purpose and happiness can’t. One thing I always look back on when we faced impossible odds was that I assumed every day that tomorrow I could lose everything. When you accept that anything can be taken from you at any second, constricting fear dissolves and you operate from a place of infinite potential and ability. You suddenly have superhuman strength."

2. Chris Grant, the owner of Grant Family Farms

"Never make the mistake of thinking you know everything about anything. Do not think you are an expert in anything. Everyday in business is a giant learning process. Do not sell yourself short by thinking you know it all, and be open to new ideas. Be aware of your competition, but don’t lose sleep over them. Like in the third grade, you need to mind your own business."

3. Kyle James, owner of Rather-Be-Shopping.com

"Never let somebody tell you that you can’t do something. If I had listened I would have quit a long time ago or never started to begin with. Find a niche, create a website and content that is the best resource available, helps people solve problems, and the customers will follow."

4. Zeb Couch, owner of OffMarketFormula

"The world belongs to the meat eaters. Those who see what they want, drool at the mouth at the thought of tasting it, and aren’t afraid to get battered and beaten in order to take a bite. Behind every IPO, every company like Facebook, Twitter, Instagram and Roc-A-Fella there’s a meat eater who’s scraped and clawed to win. Guaranteed. If that sounds too painful, too unappealing, this life just isn’t for you."

5. Mike Townsend, the founder of HomeHero

"An important lesson to remember is to constantly grow your skills don’t be intimidated by things you don’t know. If you don’t know how to code, design, or raise venture capital, just jump in and try. Have the mentality that you will solve any problem that comes your way and you will attract talented people looking for a leader."