I have a really rotten memory - you can't imagine how it feels to wake up with the first verse or two of a poem running through my mind and I rush to type it (I leave the pc on all night just for this) but as soon as I write the first line, the rest are either playing peekaboo with me or rush off to some more exotic mind.
I hold that the words that come to me do not belong to me and if I do not do them justice, they'll go in search of a mind more receptive and talented than mine. However, while I am writing, they are mine. Afterwards they belong to all those minds who enjoy or grow by them.