In most cases, my unfinished paintings stand at about 80% done---but that 10% can entail a few hours' work, and when you multiply 2 hours by 30-40 paintings, that's no small feat.
And the other issue: some of those paintings I do bring to completion end up migrating to the "forget about it" pile after all! But I won't know until I push through to the very end and FINISH.
Like the old sports slogan "the thrill of victory, the agony of defeat"--I sometimes don't know exactly which paintings will soar to great heights, or which will end up in the recycle bin. But, luckily for me, I enjoy the physical process of putting paint onto paper or canvas. And I do have a few pieces that I rescued and brought to a surprisingly nifty conclusion. So, no matter what the outcome is, I feel like the time I put in on my paintings is worthwhile. No, it won't end world hunger, or bring peace to all nations, but the season of finishing gives me a great deal of personal satisfaction and prompts me to start the new year with a fresh outlook on my art.