I thought my story idea was original?

I had an idea for a short story once and wrote it. I sent it to a magazine and they rejected it. But about three years later I saw the same story on an episode of 'Alfred Hitch Presents'. It wasn't the EXACT story but the plot was the same and the characters were a little similar with thier problems and the story's conflict. I don't think my idea was stolen but what are the chances of my idea being the same as some screen writers. (I think mine was better, though) Any answers? Thanks.