Adam over at Author's Echo has a post about stealing ideas. He says you can't NOT steal ideas. As far as it goes he's right. Ever heard the story where a boy and a girl fall in love despite the fact that they come from different worlds and their parents are against it? Yea, that's just about every book from Romeo and Juliet to Twilight.
We write about human emotions, ideals, dreams and anguish. There's bound to be some overlapping. Authors interpretations are what makes the ideas special.
Still, I know of writers who were in the middle of a story and came across an already published book (or movie) that was so similar to theirs they stopped writing it. It happens. I've read some books that were so similar I wondered if the authors were related or if one of them was "influenced" by the other. Actually, there's a few of those I'll be wondering about into the next life. And it does make me worry some as I write. What if I'm not unique enough? I'm not worried enough to stop writing. I did however, do checks on amazon and the library to see if I could see anything like what I was writing. Well, agents do say to know your field....
Has this ever happened to you? Do you worry about it?