Worry, about the 'thousand and one' details entailed. My one-track mind has to be relieved of these worries completely or I cannot get started working on my paintings, or even get to sleep at night.
I feel that when I am painting, it is a form of worship. I see how wonderful nature is and how wonderful art is... and by trying to produce these works of art, I feel that I am just showing my appreciation of these creations.