A few days ago, Kloude posted about how she first started writing, when, and why, and asked others to respond. So...
I started writing for a few reasons... I think I was 10 or 11 at the time. Probably the main reason that I started writing was because I hated the ending to Lord of the Rings - crazy, but true (hey, I still don't like how sad it is). After I finished reading Lord of the Rings, I decided that I was going to write a sequel purely for my own enjoyment, just so the ending didn't bug me. Obviously, that project got ditched pretty quickly, but that was the big thing that got me started writing.
The second reason why I started writing - it drives me CRAZY when my favorite characters die. And it happens in almost every single book I read! It's safe to say that I'll usually be sobbing at some point in a story when my favorite character dies some heroic death. That is soooooo depressing. So a big reason I write is so that I can have awesome characters that don't die at the end of the book. There's usually a death or two in each of my stories, but it's rarely a character that I absolutely adore (I think I've killed off a favorite character... once. And then I missed her so much that I brought her back. I'm terrible, aren't I?).
What else... apart from those two main reasons, I also started writing simply because I wanted something fun to read. I needed a few characters who weren't all wishy-washy and docile, a villain that it was a pleasure to hate, a liberal sprinkling of magical creatures, crazy escapades, zippy comebacks, and just some all around fun.
Writing is awesome.