White people understand racism as a matter of etiquette. They teach their kids its wrong to say certain things but don't teach them about how white supremacy has been a part of American culture for hundreds of years.
The way white kids learn about racism is "once upon a time, there were racists all over the place(except for your family) and there were racist laws and regulations, then one day enough black people said 'no' and white people had a change of heart and now America isn't racist anymore"
Somehow the hundreds of years of racist thought, practices, media etc. Just disappeared because enough people felt bad and America isn't racist anymore. Those people smiling in the lynching pictures or screaming at the black kids trying to go to school had a 'change of heart' like the MF grinch and their hearts grew 4 sizes bigger and they stopped hating black people and teaching that hate to their kids.
Obviously thats bullshyt and when educators even try to teach the real story you end up with parents freaking out over 'critical race theory teaching kids to hate white people and hate America'