Socialists and communists believe that, by erasing history, that it never happened. They’re good at changing history too, in the hopes that people will follow their version and change their lives accordingly.
What socialists/communists/progressives/liberals/democrats are really good at, is BS. Unfortunately, about half the population prefer BS instead of the truth.
Since HISTORY for most people begins a few years after they are born this is somewhat true. Our public schools are certainly not going to refresh their memories.