Don't you love that feeling of comfort  with things you know and learned a long time ago or a skill that you have practice over and over. However, we all experience constant change - some smalls (like constant software upgrades), some bigger (like life changes). On top of that we learn new things all of the time. 

As things change we often experience doubt.  We can doubt that we can do something. This doubt may be enough to stop you from trying something new, like a new painting or a new subject to paint.  Doubt may event stop you from improving your skills.

Alternatively, doubt presents us with the possibility to see things in new ways, to gain new knowledge or ideas, and to try new things. 

WIP