It is only when one makes the personal connection and sees the huge gaps in family trees, deals with people who grew up with no grandparents, uncles, aunts or cousins that one understands the true impact of the Holocaust.
I know this personally because my mother-in-law grew up that way. Apart from her parents who rebelled and moved to pre-state Israel in the 1930s, the entire extended family was murdered by the Nazis in small town a few 100km east of Krakow!