When I was in college I spoke to a Chinese exchange student about Tiananmen square. They had a vague idea that something bad happened there, but they didn't know any details. They had never seen the picture of the person in front of a tank before. They had a belief that lots of bad things happened in China's past, but it's worth it because they are no longer poor.
There's a difference between knowing a subject is taboo, and having a real understanding of the subject.