I can see some people aren't quite happy with this story. Perhaps I should explain: You see, I have nothing against Mary Sues in general, just the ones involving characters that happen to be perfect in every possible way and just rub me the wrong way. I don't mind SI fics, as long as they're either not that serious or if the story does not revolve completely around them. Or if the story is well written, that's also an important factor. One example of a SI fic I don't particularly like is Assault of the Elementals by Adamant. While the story is admittedly not too bad, I don't like how the author makes his character quite literally the High God of the Digital World.
So to sum things up, I like Mary Sues/Barry Hues and Self-insert fics as long as the characters are not too cliché or perfect and the story itself is pretty good. I'm not ashamed to admit I did the same thing before I actually knew what Mary Sues were, but I'm satisfied with the stories I wrote them in, because I think I did a good job. (I think.)
And by the way, the actual moral is not to talk to strangers. I just used Mary Sue to demonstrate my dislike for the overdone and cliched ones. After all, why do you think the title means "Beware of the Dog?"