How many paintings have you started but never finished, and why do you think that is.

I can't tell you how many times I have sat down with a really good ide or image to paint and started it but never finished. Some it's like my style completely changed. Or I progressed in a way that I felt I couldnt sit back down to it.
Alot of my artwork also has been attached to feelings and or emotions. A lost love, or a friend no longer a friend who had inspired me or influenced me to start the piece, with full intention of finishing. But alas it was either too hurtful to work on it. Or I had moved on and didn't want to relive any of the feelings.
Sometimes I will go months without even thinking of art. Or it just becomes a task in my mind losing all creative flow. So what is it that is within you that stops you from finishing? What is it going to take to get you to work on it again?