Many people can write one story, but writing many stories is a different thing. I often think the worst thing to happen to a writer is to have a big success with his first book. Unless the writer has done a lot of writing before, he will never have learned his trade properly. There are techniques and skills to be learned for writing as in any profession or trade. All the stories fall into certain patterns of behavior which we call plots.
Plots are nothing but a constantly recurring human situation, patterns of behavior.
It's my belief that ninety percent is based on just twelve to eighteen plots, and you can find them in any metropolitan newspaper in any given week. The same plots used by the ancient Greek dramatists were also used by Chaucer, Shakespeare, and Dickens.