A Mary Sue, in fanfiction, is an author who inserts herself into the story as an original character. There are many ways to identify the Mary Sue; it usually includes a Tragic Backstory as well as feeling Terribly Sorry for the Mary Sue.
As I read about the recent fake memoirs, especially Margaret Jones/Seltzer, it struck me -- these are Mary Sue memoirs! Except instead of being fanfiction about fiction (TV, Movies, books) it's fanfiction about real events; with the writer needing to be a part of the story. Better yet -- as the New York Times puts it, they need to steal another's suffering.
There is a huge difference between having your own version of your childhood and your life, and, oh, changing the version so now you're a foster child instead of a child of privilege, or, better yet, rather than being raised by uncaring adults, you're being raised by caring wolves. Regarding the first, anyone who has siblings has seen this firsthand, as you compare childhood stories and realize that your memories don't always mesh. We, the readers, get it; why don't the publishers and those who defend the Mary Sue Memoirs?
Thanks to MediaBistro - Galleycat, I find some of the worst nonsense defending these Mary Sue Memoirs. It's not quite the "anytime a person writes it's fiction, get over it" argument I've read (good-bye, non-fiction!), but it's just as bad, as some Self Important Ivory Tower person says, it's ludicrous to expect memoir to be "documentary truth." Rather what is important is whether it is "meaningful" or has "higher truths". By using this definition, we get to sidestep the issue that Real Former Gang Members or Real Holocaust survivors are the ones with the "truths" and facts to be writing the memoirs, while the rest of us who want to write about these things can do so using fiction.
And, of course, it gets both better and sadder. Because both of the most recent memoirs were about people living the Mary Sueness well before any book deal. Seltzer/Jones went so far as to involve her child, who either (a) was raised believing this or (b) was taught to lie for the nice reporters from the New York Times.
I used to wonder why the Little House books were not published as non-fiction. Her name was Laura; she had a sister named Mary; she really lived in those places. But Laura Ingalls Wilder and the publishing world back then knew the difference between fiction and non-fiction. It makes perfect sense, now, just why those childhood stories are in the fiction.