A memresistor changes its resistance -permanently-.
Pass a current through the top conductor just briefly, and the bottom titanium layer becomes, and stays, conductive. Days or years (or nanoseconds) later, pass a current through the bottom conductive layer, and the two titanium layers reverse their state, with the top layer becoming conductive.
Even after removing all source of electrical power, these memresistor devices remember their state; which of the two titanium layers is more conductive doesn't change or decay.
Oh. I didn't catch that. Thanks!