By Carol Roth, author of The Entrepreneur Equation: Evaluating the Realities, Risks, and Rewards of Having Your Own Business (BenBella Books, March 2011), recently featured on Portfolio.com

Thinking of starting the next Twitter, Groupon, or Facebook? With these remarkable successes permeating the media, most aspiring entrepreneurs don’t get to hear about the reality of business ownership for 99.99 percent of those who start a new venture. Here are five of the most common myths—along with one absolute truth—about entrepreneurship.

Myth 1: You get to do more of what you love.

Everyone thinks that if you love to do something, you’ll get to do more of it when you run a business. Wrong! When you run a business, you have to do and oversee many functions, from marketing to accounting to handling employees to dealing with customer service and more. So at the end of the day, you actually spend less time doing whatever it is you enjoy doing. Your job as an entrepreneur is not to do one thing—it’s to run a business. So, if you love to wear multiple hats and are jazzed by the idea of managing all aspects of an operation, and you think you’ve got the chops to do it, you’re headed in the right direction. If not, beware of the myth.

Myth 2: You are the boss!

Sorry, but wrong again. When you have a job, a handful of people have control over what you get paid, your hours, who you work with, and other professional decisions. When you’re the boss, guess what? You’ve increased the number of bosses that you have—exponentially—because every single customer will be influencing your decisions. Now you have hundreds, maybe thousands, of people you need to report to, who have control over whether you get paid, when you work, etc. Oh, and for an extra-special treat, each customer has his or her very own agenda. And if you have lenders, investors, a landlord, or a franchise parent company, well, they all have control over you too. You have now even more people to report to than ever before. Not exactly the picture of being in control.

Myth 3: Business is about you.

We have more products and services available to us than we would ever want or need, which makes today’s entrepreneurial landscape very different than it was just 50 years ago. If there is a gap in the market that customers are desperate for a solution to and willing to pay for, that’s a darn good reason to start a business. Remember, Ray Kroc didn’t start McDonald’s because he was bored or unfulfilled; he did so to meet a customer need. If you want to do something that’s all about you, seek out a hobby or maybe get a job, but don’t start a business. Successful businesses are all about servicing customer needs.

Myth 4: It’s easy!

There is a reason the word scheme usually follows the phrase “get rich quick.” Businesses take a long time to build, sometimes taking two years or more to even get their legs underneath them. Business ownership is not a magic bullet for financial security and you should be prepared to be in it for the long haul. It’s called work for a reason!

Myth 5: You can equals you should.

Just because you can do something doesn’t mean that you should, that you will be successful, or that it’s the best choice for you given your goals, circumstances, and opportunities. You have to look at the rewards of your opportunity and see if they justify the risks—and I’m talking both financial and qualitative risks and rewards here. Far too many people trade their salary and risk their savings for an opportunity where they’re making the same or less money, working more hours, and having more stress. In the game-show world, they call that trade a “zonk.” Don’t get zonked—make sure that the risk/reward trade-off makes sense for you and that you have the opportunity to significantly improve upon your current situation or do better than other situations that could be available to you.

And the one truth: The Rule of 3.

OK, this is my way of cheating three “truths” into one, but go with me here. Here’s what you can take to the bank. Everything is going to take three times longer than it should to complete (whether your legal contracts, getting revenue, or getting your website up and running), will cost three times what you have budgeted, and will be three times more difficult to execute than you expect. Even if you think you’re being conservative or realistic, you probably are underestimating the time, money, and effort required to make your business a success.

This article was recently featured on Portfolio.com