I think Jonathan was almost right.
Yes history and yes memory, but more than either, I think to be a Jew is to have a sense of destiny.
I don’t think I’ve ever met a believing Jew who does not feel the same way: as storied as our past has been, as perilous as our presence is, we are absolutely certain that our people is eternal and our future is glorious - more magnificent than anything in our history - in human history. And that the glory isn’t selfish, but one shared with all humanity. And it doesn’t matter to us if that future is tomorrow or a thousand or more years from now; that baseline assumption animates every perception.
I do think that the sense of destiny - even eternity - is rooted in our collective memory, but it is the sense of destiny that provides a sense of purpose and resilience that undergirds Jewish identity.
At least that’s this Jew’s opinion…