When you get to your office in the morning, are you happy to be there? Do you dive into the day's tasks with enthusiasm? Or are you counting the minutes until you get to leave?

If you don't love what you do, no matter how successful you are, and no matter how much money you're making, you should probably consider doing something else. Many people seem to believe that loving what you do is a luxury. They plan their careers on the principle that making a decent living is necessary and that having work that you enjoy, and--more important--find meaningful, is a nice add-on, if you can swing it.

I think that's dead wrong. Making a living is essential, but so is having work that you enjoy and care about, and that you believe has real value. If your work is missing any of these features, and you don't see a good prospect for things to get better, it's time to consider doing something else. Here's why:

1. Work takes up a very big chunk of your life.

The average American spends 47 hours out of every week working. That means that during your working life, you'll be spending over 40 percent of your waking time at work. Or maybe much more. If you're running your own business, or working in management or in any of today's high-pressure, long hours professions, you likely are working even more than those 47 hours.

There's no getting away from it: Work takes up a huge proportion of our lives. None of us know how long or short these lives will be. But we do know that people who are dying often list the amount of time they spent working as one of their top regrets. Working takes you away from your family and from other activities you love. If you don't enjoy it or believe it serves a valuable purpose, then work isn't worth that investment of your time.

2. If you don't love your work, sooner or later you'll start sucking at it.

Oh sure, you might be good at the mechanics of something you don't particularly enjoy. But only for a while. Every industry is rapidly changing, and to stay good at something you have to keep up with the changes, which means constantly paying attention and constantly learning.

For most people, that means paying attention, reading, attending events, taking courses, and generally spending a lot of time outside of traditional work hours getting and staying up to date. It's going to be tough to get yourself to put in those extra hours if work is just what you do to pay the mortgage. And if you don't put that extra time in, you will fall behind.

3. You can't fake passion.

Even if you yourself can do a good job at something you don't like, you're going to run into trouble when you take on a leadership or sales role. You'll have a hard time inspiring deep caring in others for whatever it is you do if you don't feel it yourself. That will become a real stumbling block whenever you make a sales presentation, give guidance to an employee, or ask for money from a bank or investor. Unless you have superb acting skills, you won't be able to create passion in others that you yourself lack.

So why try? Most of us have a variety of career paths or professions that fit both our values and desires. Over your lifetime, you're likely to spend about 99,000 hours making a living. If you don't want those hours to seem never-ending, better spend them doing something you love as well.