Write it down. Not just to remember it, but to forget it in the right way. My notebook are a kind of materialized subconscious, a hard-copy memory and its invisible substrata, following their own rules. More than once I have been surprised to discover that an idea I thought was new and original, something I set down in a notebook yesterday, is already contained in another note from years before. Sometimes the second version repeats the first, almost word for word, across the space of a decade. The earlier version, once brought with clarity to the surface, has been covered over again by layers of yellowing paper.