arduous: requiring great physical or mental effort; difficult to accomplish; strenuous;hard to endure; harsh;hard to overcome or surmount; steep or difficult

When I think of arduous tasks, I never really think of something that I enjoy doing as being arduous.  However, the more I think about it, the more I realize that my greatest passion, which I've only recently begun pouring my whole self into, is quite arduous.  But perhaps this is a good thing.

Good things in life are worth working hard for and maybe I wouldn't feel quite so gratified if I hadn't had to spend countless hours straining my eyes staring at a computer screen, numbing my fingers pounding endlessly on the keyboard, and frying my brain trying to catch that one word I've been trying to think of that has eluded me effortlessly. 

If things came too easily I'm sure I'd either sit there staring in disbelief, or end up convincing myself that I don't deserve it since I didn't put enough work in.  So, although at the time an arduous task may not be an enjoyable one, at the end of the day I'd like to think it was at least worthwhile.