I always groan when it comes time to edit a novel manuscript. For me, the 2nd and 3rd drafts are the least fun (except when I find something missing entirely and get to write something new). By this point, I've already done a lot of re-writing, as I don't consider my 1st drafts complete until I've fixed the glaring continuity errors, and name changes, and major motivations, etc--all those things that stick in my head and won't leave me alone until they've been attended. Of course, as I read through the manuscript, I always discover many more things that still need to be fixed. I take copious notes.
The strange thing about this novel, Within Us All, is that one of its major underlying themes is the artistic struggle. It involves a young man commissioned to paint a dark mural and his struggle for perfection with it, that drives him into a sort of obsessive frenzy. So, as I begin the next draft, the difficulties I face are mirrored in the text I edit.