Now, I -do- understand that people like to talk about themselves--this
is also a childish impulse that people grow out of (the cappuccino
silver-spoon carried-through-life adults are the exception). All
self-insertion fics are the products of minds that are (still) immature.

This is an indefensible stand.  Many great authors have written memoirs,
autobiographies, and autobiographical or semi-autobiographical fiction; 
some but certainly not all of them can be classified as "immature."

One particular example among many is William Styron's "A Tidewater 
Morning," a collection of three stories featuring the author as a central 
character.  I hardly think the author of _Sophie's Choice_ and _The Confessions 
of Nat Turner_ can be classified as immature.  Or if you follow the best
seller lists, try Frank McCourt's _Angela's Ashes_, a memoir and an 
example of a story about its author that is anything but immature.

People talk about themselves for their whole lives; we know ourselves 
better than anyone.  While these novels are probably better than any 
self-insertion fic, they stem from the same impulse; the desire to 
record and guess at our own reactions to the things that happen (or might 
happen) to us.  The idea that everyone who talks about themself is 
immature, which you clearly state in the above paragraph, is ridiculous 
and offensive.  

Thomas Schmidt
Tschmidt@tcon.net
http://nabiki.newberry.edu/job/