Thats most of everything though. The hardest part of finishing your programming project is the last icky bit that you really didn't want to do yet, or bug fixing, or polishing. The last part of painting is the touch ups, and thats also the longest part. Its much easier to just come up with a sketch of a piece of art (or any project) than it is to get into the nitty gritty painstaking details that it requires before you can say its finished.
I've finished 3 novels, and one remains half-written. My downfall is always the world building - I often find it's more fun daydreaming the world rather than having to deal with cantankerous characters who refuse to go where the plot needs them to go, and always argue about everything.
I'll leave it to the reader to decide if that is okay or not. For me, I know I have too many unfinished projects and so my stories will remain dreams that never get written down.