It has occurred to me that you should really walk around with an ideas diary. I mean it didn't just occur to me because I've known this for years. For both artists and writers.
Ideas are very fleeting things. Some of them are worth keeping. Some of them are best forgotten. Some of them probably are only temporarily forgotten, and come around every so often, but because we have forgotten them we mistake it for a new idea.
Today I am thinking this because I'm editing my story and I have completely forgotten the plot, even though I know the general plot, the particular, incident by incident has been forgotten. The WIP is good. I know it is, but I still need to work on the editing. It needs upping the drama, without being over dramatic.
Over drama is worse than underdrama.