I suffer the opposite malady to my friend Lisette over at Textile Seahorse, who confessed recently that she actively resists finishing. I fret about not finishing.
Of course I have UFOs in my past - many still in the cupboard. Things that I fell out of love with, things that I stuffed up and things that I would rather forget. But that's the point, I cannot forget them, they haunt me, I feel terrible guilt about them. The waste.
I recently found a jumper I had finished knitting when I was at uni (some time ago!). I just hadn't sewn it up. I have no idea why I stopped, but over the years I had remembered it with self recrimination. So I got it out of the bag with good intentions, even if it was out of date I could finish it off, but the moths had got there first. It was finished. :(