Extraneous keys: Often when I am cleaning or after a few moves, I always find a few more keys accumulate. Afterawhile, the keys become forgotten. Suppose you've found a bag of keys and you've discovered what they open. Tell us about your keys and what they unlock?
A key could unlock another place you had, maybe a car? Is it a spare key? Does someone else have a matching key? Think about other ideas your key could unlock? A memory, a story from your past.
Or begin with one of these sentences: This key opens ... (repeat this one several times and see what the repetition results in.. often I surprise myself, or if one completion has a lot of juice for you, go with it).
If this key would only open.....