To be completely ignorant of the collective past seems to me to be another state of amnesia; you would be untethered, adrift in time. Which is why all societies have sought some kind of memory bank, whether by way of folklore, story-telling, recitation of the ancestors--from Homer to Genesis. And why the heritage industry does so well today; most people may not be particularly interested in the narrative of the past, in the detail or the discussion, but they are glad to know that it is there.