Maintaining your interest in your work is a delicate dance, not unlike limbo. Set the bar too high and it's just no fun; there's no point to it -- and set it too low and you just about break your back trying to scoot your way under. In your working life, while you may have an outstanding gift for what you do and may even be passionate about your chosen field, there are always moments when you are just doing your work because you need to do your work, and without enthusiasm or inspiration of any sort.
The book "Flow" explores the relationship that people have to the interest level of their lives. In terms of work, play, relationships, hobbies and general satisfaction, whether you're an artist, teacher or lawyer, athlete, pharmacist or engineer, getting to the "flow" state means that you're in an optimal state of experience. You are not too challenged or too competent; the activity is neither too hard nor too easy. http://www.amazon.com/Flow-Psychology-Experience-Mihaly-Csikszentmihalyi/dp/0060920432
What Mr. Csikszentmihalyi tries to explain in this wonderful look at the heart and soul of being engaged with an activity is that in order for us to lose ourselves in our work, our play or our relationships, we have to feel that the interest level and the challenge level are suited well to us.
In our working lives, we tend to lose interest when things are too complicated, if the demands are too intense or unattainable, or if we feel we are failing. It's a story of giving up. We feel that things are too unreasonable or too skewed. We feel that what we have to offer is not being accepted, or we feel that we are not trained properly to meet expectations. So we stop being interested in trying hard because succeeding doesn't feel within reach as a possibility.
Fixing this may or may not be possible. Taking more time to get training, asking the right questions of the right people, learning and studying more, taking a course or doing an internship with someone who is an expert in the field can turn things around dramatically. But if you're not compensated, supported, or given time to embark on these efforts, it simply may not be possible.