Today is the 26th anniversary of events in Tiananmen Square that some call a massacre, some call a tragedy, but which many in China can't — or don't — talk about at all.

In Hong Kong, where discussion of 4 June 1989 is allowed, around 100,000 people are expected to take to the streets, but on the mainland only a few personal commemorations will take place. For example, a small group of mothers of those killed in Beijing's main square will likely undertake some small vigil. Like always, their phones will be tapped, and they will be closely monitored by authorities. This year, under Xi's more stringent surveillance of the internet and other forms of social expression, monitoring is likely to be even tighter than usual.

Yet many Chinese young people do not know about what happened in the centre of Beijing 26 years ago. And perhaps more surprising is that those who do know about it, or are given information about it, simply aren't interested.

At my Chinese language school in Beijing, I remember clearly an earnest American student asking his young Chinese teacher in hushed tones if she knew about Tiananmen. When she said she didn't, the student surreptitiously handed her a photocopied article from a Western magazine with photos of the event. She politely accepted, and said she would read it and talk with him about it at their next lesson. The next week the student asked rather breathlessly what the teacher thought about the article. She replied, 'Oh, thank you, but I didn't really have time to read it; to tell you the truth, it was a bit hard to get through.' The American student was astounded. He had expected shock or at least angry denials, some kind of foundation for debate, but got uninterest and indifference.

My experience teaching undergraduate students at a university in Beijing was similar. I never raised the issue in class, but in smaller groups or one-on-one discussions, students either didn't know or, if they did, were not shocked, and certainly not moved to thoughts of political resistance or even reform.

This does not (entirely) reflect a lack of access to information. Most students and young people I know in Beijing have access to technology that allows them to get around 'the Great Firewall' that prevents free access to online information. However, this is mostly used to get to websites about sport or celebrities, or to download American  movies.

What this lack of interest reflects is the strength and coherence of a national identity in which the Party and the state are inextricably interlinked with 'being Chinese'. Being seen by society as a good, proper person means being seen as a good, proper, Chinese; and that means while it is acceptable to criticise corrupt officials or irrational laws, it is inconceivable to question the system as a whole. This is not to say that the Government does not exercise its power in a strict and obvious way; it certainly does. However it is skilled and practiced at knowing how to co-opt and put down dissent if it does flare up. Aligning the state and the party is a part of its political power.

Understanding the strength of this sense of national identity, combined with strong government power, helps explain why there was virtually no 'contagion effect' from the Hong Kong democracy protests on the mainland. It helps us better understand why the US continues to be portrayed and perceived as a meddling and insecure troublemaker. It should also help us to understand that any efforts to influence Chinese attitudes or behaviour need to work with this powerful national identity in order to have any chance of being effective.

For the moment, though, I'm thinking of the people who were injured or killed, and their friends and families, in that sunny, open square in the heart of Beijing 26 years ago.