Those of the silver generation often joke that the reason they can’t summon up facts quickly is that the mental reference library is fuller than that of the young. But a new study suggests it’s not quite that simple. A crucial reason our memory falters, which has received relatively little empirical attention, is that older adults become less efficient at ignoring stored information irrelevant to that which they are trying to target. For example, the name or fact you are trying to recall could prompt “task-unrelated thoughts”.