I finished my newest colored pencil artwork a few weeks back. It took me 3 months of working 1-2 hours a day to complete. This is, by far, the longest I have spent on any single piece of artwork in my life. It is also a big leap forward, in my own opinion.
It seems to me that my art has been improving and maturing rapidly in the last few years, and I attribute this to both consistent practice and patience that must have come with age. I remember a time when I would have said that if I couldn't finish it in one sitting I wasn't interested in doing it. Colored pencil is a bad medium for the impatient though. It is very time consuming to create the kind of detail I want to render.
And, surprisingly to myself, I find I really enjoyable to work on something longer term. Though there were times I thought I would be drawing feathers forever, I found that most of the time I spent on Raven was quite enjoyable.
Though I am taking a break and puttering around with some other faster projects, I am already looking for the next big thing.