One of my bestfriends recently wrote me a long letter on the hardships of being unemployed. She took a job a month ago and resigned last week, reason being that she didn't feel like she was right for it. After getting her second degree as an illustrator, she had approached an illustration agency to draw. Insted she was offered a higher position to manage artists. While she tried to like the job, she just felt unhappy and directionless. So against "common sense" she quit. She explained to her boss that by staying in the company, she was doing a disservice, not just to herself, but to the company too as she was not contributing effectively to its cause.
I applauded her on this, as I've been the one hiring people and it irks me when people feign enthusiasm and interest for a job, but they really have no plans to help themselves or help their company.
No, this is not a lecture on loving your job and being grateful. This isn't about quitting a job that you find boring. It's about being considerate (don't waste your time and other people's) and realizing when it's time to move on and move up! 
I can say this because I went through this before I joined this company. I was in a job that I hated and wasn't very good at. In my arrogance, I looked down on the peopel who enjoyed it and worked very hard. I liked to believe that my "real" life was the one that happened after office hours. How wrong. ALL of it was my life, and my distaste on what I spent 8 to 10 hours, 5 days a week, spoke volumes on my maturity.
Well, I am fortunate to have come across a job that I really enjoy. That in itself is already rewarding.
What about you belles? How are you with your job?