The holocaust, probably because I was born just after the war ended and knew Jewish survivors from an early age who came here to New Zealand as refugees at that time - my childhood doctor was one, and he had badly scarred hands from being forced to work in lime pits with bare hands.
Some survivors preferred to emigrate from Europe to Australia and New Zealand because we were as far away from Europe as possible, and that found that distance reassuring, as well as the social democracies that both countries were.
By the time I was 8, I knew about children my age being gassed to death, shot in the head, torn apart by dogs in the camps, and because of my age I could horrifically identify with them and realised that adults could be so murderous to innocent children. It made a very deep impression and I have hated fascists and fascism every since.