Most of us remember autobiographies from our Elementary School book-report days. I've personally always found the concept of them to be kind of conceited--writing a book about yourself, and how awesome you are. However, around the time I finished my first manuscript ("Whatever's Left," which happens to be available on Amazon.com from Solstice Publishing . . . since you mentioned it and all), I got to thinking about them in a different sense.
Ask most authors, and I'm sure a lot of them will admit to injecting elements of themselves into their characters. It's really almost impossible not to. When you're creating an entire person, and trying to generate a pseudo-relationship between them and your reader, you've got to round out the edges, scuff up their knees a bit, and give them some heart. And sometimes what you end up with is a character who bears at least a slant resemblance to you.
I was guilty of a lot of autobiographical fiction with my first novel. I started it my freshman year of college, when I was nostalgic for home and how things used to be. The first draft of that book had characters named after old friends, scenery nearly identical to the town I'd grown up in, and a main character who really had a voice similar to the one you'd find if you cracked open my diary.
As all writers do, I edited and re-drafted and got better each time I did, until I was satisfied with the final draft, and also satisfied that I'd made it into its own story, instead of a what-could've-been version of my own. And then came the miracle and curse of people actually reading it.
Since I sent "Whatever's Left" to my first beta reader, I've gotten everything from "Is this supposed to be you? She has brown hair like you. It says so right here" to "You can't have the dog named Moose. Your dog is named Moose." (The second thankfully came from a good friend and fabulous beta-reader who caught my faux pas before any publisher was remotely interested in the book)
So I guess the conclusion I've come to is that it's impossible--at least for me--not to put a bit of yourself into your characters. When you think about it, you put so much of yourself--in the blood, sweat, and tears kind of way--into a manuscript, when it's finished, you really should find something familiar there.
But I will say this as well: I'll never write a main character with brown hair again :)