Think back to when you were five years old. One of the most common questions you were asked was, "What do you want to be when you grow up?" You were so certain at the time that you were going to be an astronaut, a dancer, or a pro baseball player. There was no doubt in your mind. Fast forward two decades: How's that working out for you? Oh, you work in finance now? Why'd you sell out to corporate America?

Turns out, if everyone ended up doing what they dreamed of doing when they were five, we'd probably have more humans on the moon than on Earth. A 2012 LinkedIn survey of 8,000 professionals found that only 30% of workers worldwide followed their childhood career dreams. In the United States, that number is even smaller: only 25%. But is that such a bad thing?

The "follow your dreams" adage, which is a quintessential element of our free-enterprise American culture, doesn't always work out in all respects. Maybe you dream to work for a nonprofit that specializes in saving an endangered species of bug, get married, have a family, and move to Madagascar. But by the time you're forty, you're a pro-bono lawyer living with your family in Maine. But hey, even though you haven't accomplished every dream, you still accomplished some. That's better than a lot of people.

Why do we stray from our career dreams so easily?

Mostly it comes from a realization that our dream jobs are unrealistic, not lucrative, no longer of interest, or are surrounded by a lot of competition. We've all seen those competitive singing shows, for example. Out of thousands of young hopefuls, only a handful will actually have a successful music career. So if you're not insanely motivated and willing to sacrifice everything, you'll just end up singing backup. But the world needs backup singers!

A certain disenchantment hits us after college, when we realize that the world is just a big game, and it's all about playing your cards right, having natural talent, connections, and luck. But we shouldn't be discouraged. Pursuing our passions as a career seems like a beautiful idea, but there are actually some reasons why it might not be the best choice.

According to career advisor Allison Green of US News, we should scrap the advice to "follow your dreams" as it applies to careers. She's not a cynic, but a realist. She says that the advice to pursue our dream careers often makes us study the wrong field in college, which won't properly prepare us for the field in which we end up working. (Not to generalize here, but acting school does not generally teach students how to wait tables, though many actors start out as such.) If you really want to be an astronaut, what are the odds that you're going to get through the incredibly rigorous stakes it takes to get to NASA? Maybe our eyes were bigger than our textbooks on that one.

The other reason that people shouldn't necessarily funnel their passions into their careers is that they don't realize that when it comes to a paycheck, baking 3,000 loaves of bread every morning might not seem like so much fun. Part of what makes our passions fun is that no one is forcing us to do them, but when our ability to produce a bestselling novel in one year will effect whether we can afford to eat, there's the same chance for stress, frustration, and burnout as we would have in any other job.

But what gets people bummed out about their current "non-dream" jobs is the guilt they feel at having "sold out." They are focused on how their jobs are just jobs, and not fulfilling some greater purpose. This leads to a loss of drive to perform, a general feeling of inadequacy, and ultimately, a greater chance of failure at that job, too.

A job is a privilege

Even if you're not an MLB player, your job is something that will help you put food on the table and provide for your loved ones. You must stay in a job to be able to afford to keep up your passions. What many workers need is an attitude adjustment. Just because your job has nothing to do with your passions doesn't mean that you should abandon your them. If you love to do something, you'll find the means to do it early in the morning or late at night.

The passion that you have for your hobbies can be applied to your job, too, no matter what it may be. You can feel passionate through your attitude and your understanding that life gives you stepping stones, that your dreams can be achieved outside of the realm of career. At the end of the day, you may not be an astronaut, but there are other ways to get to the moon.

For more information about how to launch a successful and fulfilling career, read this.