Mine is erratic.
At school, even though I found most subjects interesting, and I studied a lot on my own on whatever subjects I was interested in learning, my homework completion rate was rather low throughout High School (before HS, the HW was so easy I would finish it on the bus ride to school).
In College, my work ethic at school, and work improved a lot. I got two degrees in 3 years of school, and gained 2 years of work experience, in the field I wanted to enter. I felt like I was setting my own direction and my life was fully in my control.
This was a time I was a total work-a-holic. Pretty much from when I was 18 through about 24-25 (through college and a few years beyond). I was actively pursuing my dreams through a career.
Some exceptions, however, were that I pretty much have always neglected my chores, and really dislike exercising without the exercise being a part of a game or something.
After that, I became disillusioned and cynical...and finally burnt-out and depressed. Since then, my effort and concentration at has wavered a lot. Some days I get a lot done, other days I get nothing done.
Also, my weaker mind-set has lead to getting sick really easily...and missing a lot of days at work.
I got my Master's in the mean-time, and grad-school fueled ideas and some meager amount of hope. However, the work load was stressful and hard to bear, and it took me 5 years of grinding through class work.
Work right now just doesn't connect to ambitions, hopes or dreams. It is just a job for me, but, for many (maybe most) of my co-workers, the work is for their careers. That makes is hard to keep my motivation on par with mt co-workers.
Currently, my hobbies keep my spirits up, and I pursue them with a decent amount of energy. Some of that energy help me at work, but sometimes the hobbies take my focus off of work too.