One idea is good, many create a story.
i think one of the most important things that a writer should have is the ability to collect ideas. Ideas make a story go from alright to good, from good the great and from great to a masterpiece.
(picture from here)
As a storyteller and writer, my stories would be completely shit if it wasn’t for all the ideas that I’ve collected. These ideas can be facts, personal stories from friends, or even people you over hear, they can be pictures, events or something completely made up.
When have an idea or many ideas that you like, you can then mold them like dough and create a Frankenstein monster of a story. This creature should take on an life of their own and when unleashed on the world they should have such an effect that it stays with people for ages.
Sadly many stories are not as great or as influential as Frankenstein, but they could be with an author that collects and molds ideas.
Stephanie Haggarty 
Good post. I love collecting ideas – little gems overheard in cafes, stories in the newspapers, pictures, moments in time, Once I was standing outside a tube station waiting for a friend when a car pulled up and someone got out. That was it. But by the time my friend arrived, I had the germ of a story about a guy who got involved with a psychotic hoodlum and… oh… well, one day I might write that one!