Erm, no it wasn't. The author started writing at age 15, and about 3 years after that it was published.
And Mattias might be a classic, but (no offense 3J, you know I like you) I can't say it was that great (though I bet many disagree with me). Just riddled with grammar errors and the sort.
Completing any writing project at such an age is amazing, but that doesn't mean make it automatically amazing.