There is nothing new under the sun, but there are lots of old things we don't know yet. -- Ambrose BierceAnything I write will have elements of what other people write, but it will also have elements of me.
A few years ago I took a week-long course in autobiographical writing. I did discover that I have a voice of my own. I also got this quote out of the course:
There is a vitality, a life force, a quickening that is translated through you into action, and because there is only one of you in all time, this expression is unique. And if you block it, it will never exist through any other medium and (will) be lost....It is not your business to determine how good it is; nor how valuable it is; nor how it compares with other expressions....You do not even have to believe in yourself or your work. You have to keep open and aware directly to the urges that motivate you. --Martha GrahamI do have a problem with comparing my writing ability to that of great, accomplished writers (especially Neil Gaiman) and feeling inadequate. Well, duuh, I don't spend 1/100th of the amount of time practicing writing fiction and poetry that they do.
When I listen to music, I always hear influences of other musical artists / styles in a particular piece. That doesn't make the piece less worthwhile on its own.