Many years ago, my grandfather-in-law was given a beautiful oak Mission-style sofa by his neighbor. This neighbor told GrandDaddy that he could keep it until he asked for it back again. GrandDaddy owned that sofa for so many years that the neighbor finally died. Fast forward more years, and the neighbor’s children look up GrandDaddy (now living elsewhere) and ask him to give the sofa back. He refused – on the grounds that the neighbor originally said he could keep it unless he (the neighbor himself) asked for it – and he was long since dead!