Sometimes I find that I have expectations. Not only mine, but others'.
As I work on a painting, even if it is for my own experimenting or learning, I am thinking about what my professor might think about my work. Is it overworked? Does it need more texture? Is it balanced?
Many times as I get ideas, I get pictures in my head of what I would like to try. Those pictures create expectations for me. Can I really get it to look like that? Can I really make that image travel from my head, through my imagination, jumping synapses, firing neurons, sending messages to the muscles to move and put the mark down...and will the image look the same when it arrives on the canvas or paper?
Many times, no. It does not. But I think I am coming to realize that might be why my professor told me if I finished something, do it ten more times. Each time will be different. Each result will be new. But there will be patterns discovered, techniques discovered, maybe even a bit of myself.