What is Need-only-memory?
1.
selective memory lapses suffered by the very young or the very old,(or the very cunning) when they are trying to skim over something they are guilty about, or dont want to confess to etc
She also had a distinctly selective and very volatile memory, something computer junkies would have called “Need-Only-Memory” because she remembered things only if they suited her, and otherwise resorted to a an extremely blank and innocent expression of pleasant non recognition which she had perfected down the years.
See