One of the most depressing things about the Tibet story is that is shows the power of propaganda. If a totalitarian state tells its people X for half a century, permitting no other point of view, people will end up believing X, however patently false X may be. Ordinary Chinese people are baffled if you suggest that the Chinese authorities give Tibet independence, or at least genuine autonomy. "But Tibet has always been a part of China," they say, genuinely surprised that you don't know this "fact." Obvious ripostes ( e.g. "If Tibet has always been a part of China, how come they don't speak Chinese?") bounce right off.
On a related theme, I was having drinks last week with a journalist who's spent the last five years in China, and he was remarking on the widespread Chinese ignorance of what, exactly, happened at Tiananmen Square. It's something that he's frequently asked about by young Chinese, he said, and when he tells the story, the response often goes something like this: "Well, then it's a really good thing the government covered it up, because otherwise there would have been a revolution."
Of course, given the history of what revolutions have meant for China over the last two centuries, this isn't quite as morally callous as it sounds at first.