I recall being very surprised when my dad, though born in Ohio in 1915 but raised in present day Serbia, reflexively stated word for word, “The Turks invaded Serbia in 1289 and massacred thousands...” I could be wrong about the details, but he clearly repeated what he learned in grade school, word for word, during his 15 years there. You had to pry accounts about his childhood, he said he was 100% American with no interest in the old country. Yet automatically repeated the 700 year old grudge.
Not far from where your father lived there where millions of Armenians who were systematically slaughters by Muslims in the time your father lived there in the earl 1900’s. Tens of thousands were crucified, because they were Christian.
I often times wonder why more people don’t bring the geonocide of the Armenians up when ever the Muslims demand Israel be stopped from defending themselves.