The task of a writer consists of being able to make something out of an idea.
"Somebody should write a book" was an ongoing conversation in my house, growing up. I have little doubt the conversation began a generation previous to my advent - if not more.
We used to talk about practical ideas for a book. Humor came up perhaps most frequently. History. We were always having ideas - or sometimes floating one, to which the inevitable refrain might be offered in return.
Ideas are wonderful, but they are just ingredients. Anyone can have high quality vanilla in their kitchen, but how many of us can put it toward a truly superior buttercream icing?
I'm no cook - but I am an author - and my work in that regard is where "somebody should write a book" became I *did* write one (and am working on another; and have strong feelings about what the third one will be).