I also thought I had my UFO stack down to one (!) and then I found a box with projects in ziploc bags... But also like you, there were reasons I had stopped working on them. The first one was because I chose to use fabric that was too thick for the pattern. The fabric was more like heavy upholstery or drapery weight. I decided to finish it up and instead of making it as big as I originally planned, finished up the 6 rather large squares I was doing and put big borders around it and will make it into a charity quilt--twin sized.
That way it is out of the unfinished box (I put quilt tops in a different category as UFOs since for them, I am content to leave them as quilt tops until I'm ready to quilt them--)--the UFOs I'm thinking of are the ones that are partly sewn together.
Now, in the process of working on those six, I kind of started more. For example, I found 12 9 patch blue and off white squares and decided to use them up by making a queen size quilt out of scrappy blues and off whites. ??? So, that is a project that I've been doing just to use up the 12 9-patches that I had.
(had to make 80+ more of those 9patches!) But I'm having fun and that is what I think is important. It should all finish out okay in the end. And if it doesn't...well, I enjoyed myself and make some pretty things in the process!