I ask myself this question just about every day, sometimes more than once. I don't always ask this about my writing. It could be anything, really. But, I do question my writing more than anything else.
Usually this question takes on a bitter, self-degrading tone: what in the world do I think I'm doing?? It usually follows a period of sitting at the computer writing utter crap. Or reading other people's writing and wondering how on earth I can think I'm a writer when I feel so subpar to everyone else. Mostly, I just think I'm posing at this little thing called writing, and after a while, someone will figure out that I'm really NOT a writer and call me on it.
Is this normal? I don't know. But, thinking more on this, I realized that I feel this way about a lot of things I do, especially things that are particularly important to me. I have a PhD and I like to think I'm good at what I do in my day job. Even still, I just KNOW someone will find out one day that I'm just posing at what I do and am not actually any good at it.
It's that niggling doubt in the back of my head, that devil on my shoulder, that says, "You're just not good enough." Sometimes, I just need to angel to pop up, slug the devil off my shoulder for a while, and whisper sweet confidence for long enough to get me back on track. That angel often presents itself in the form of my writer and non-writer friends, my husband, and my family. Even still, I only really overcome that festering thought when I push it away, ignoring it for a time.
I don't think I'll ever feel completely confident in anything I do. I've always been this way. Even when I was young and competed in choir or worked my butt off to do well in school. I always felt like I was pretending at being a musician or a good student. But just like I succeeded in those choir competitions and I got good grades in school, I know, deep down, that I AM a writer. I may not be a great one or an extremely successful one, but I AM a writer.
Do you ever feel this way about yourself? Even if you don't write fiction, do you ever get like this in other things you do? Or is it just me? :-D