Just look at tolerance for addictive activities. Compare 1970s vs 2010s and later.
Or the desire to coddle vs steering kids in the right direction. Schools completely drive what kids find acceptable and not acceptable socially. It changes over time depending on what the school district finds appropriate.
Even US presidents, 10 years ago Washington, Lincoln were unblemished, today they are complicated figures with defects. But I think you can look to the USSR as well. One day someone is a hero, the next they are counterrevolutionaries and schools follow the dictum.
