Is Editing One's Own Work Really as Easy as it Seems?

I've been a freelance writer and editor for just over a year now. During that time, I've edited three books, and am about to begin editing another. I've also edited numerous articles for clients. Although I find editing enjoyable, I have to admit that I also find it difficult at times, perhaps due to my perfectionist nature. When I'm editing someone else's article or book, I agonize over word choice and sentence structure, looking up synonyms in online dictionaries and questioning whether I have truly improved another writer's sentence, or just changed it. Often, I will end up editing my own edits multiple times! Unfortunately, my desire to make sure every sentence and every word within it sounds perfect results in me frequently having to work longer hours than I should be at my current pay rates, but I guess that's just the way the cookie crumbles (I just can't half-ass a job, even if I'm doing it for peanuts!)

However, recently I completed my own novella as part of April's Camp NaNoWriMo challenge. For those who are unfamiliar with the challenge, participating writers agree to attempt to write 50,000 words within one month, normally with the eventual goal of turning those 50,000 words (or maybe more) into a real novel. I'm proud to say that I finished the challenge, and have about 52,000 words written at the moment. Therefore, I've decided to start editing what I have before deciding whether to add to the book or not (I likely won't, as I have gone through it in its entirety several times, and I believe the plot is best left as it is). When I started editing my own work, I thought I would agonize over every sentence and every word as I do when I edit the work of others, but that wasn't the case. Instead, I finished editing the first chapter quite quickly, with no drawn-out analyses of word definitions or frequent trips to Grammar Girl (www.quickanddirtytips.com/grammar-girl) to make sure I'd been following grammatical rules to the letter.

At first I was just happy that I had buzzed through the task of editing my first few pages in such a speedy manner, but then I started to wonder, why is it so easy for me to edit my own work? Perhaps my work is of such a high quality that there really aren't many edits to perform (dare I hope that this is the case?!). Perhaps I'm less picky because I'm not getting paid for editing my own novella, and don't feel that sense of responsibility and accountability toward someone else that I would when editing their books and articles. Or, worst of all, maybe I can't see faults in my own work as well as I can see faults in the work of others (if this is true, and I suspect it may be, I guess I'll have to recruit some outside editors!). Some fellow writers have actually told me that they're more critical of their own work than others' work, but that doesn't seem to be the case for me, at least with this book (I'm a bit more critical of my articles when I KNOW, before editing, that they're going to be published in an online magazine, and people will read them. I'm planning on self-publishing my book, but there are certainly no guarantees that a single soul will read it).

To any other writers out there who may be reading this, do you edit your own work? Do you ever edit the work of other writers? Which do you find easier, and why?