To understanding how forgetting can be useful, it"s important to first recognise that a memory is never simply strong or weak. Rather, the ease with which you can summon up a memory (its retrieval strength) is different from how fully represented it is in your mind (its storage strength). The name of your parent, for instance, would be one example of a memory with both high storage and retrieval strength. A phone number you held in your head only momentarily a decade ago could be said to have low storage and retrieval strength. The name of someone you met a party mere minutes ago might have high retrieval but low storage strength. And finally, the lyrics to a song you"ve sung thousands of times but which stubbornly elude you, as you gaze out from the stage of the Worcester Centrum, would have high storage but distressingly low retrieval strength. Given the right cue, however – if your audience were to feed you the opening lines, for instance – the retrieval strength would snap right back.