Being Chinese in China has almost nothing to do with the government. It's a cultural belief that's persisted for centuries. Don't expect that to change at "at the drop of a hat".

It's not a particularly unusual belief, really. All cultures have an in-group/out-group division. OP is just missing traits this specific test requires.

A century is not a very long time in Chinese history. In fact, yes, for the Chinese, a century may very well be a "drop of a hat".

Never underestimate the possibilities of change in China.

True, but as opposed to, say, France, the dropping of hats in China may take centuries, if not millennia.