Human memory is very error-prone. Although we have our own memories of a person, it seems that this person is like this in memory, but memory is very easy to make mistakes and change. When a person appears in front of us in a way that is beyond our memory, we may be surprised at first, but then we gradually feel that people will always change. This person is different, probably because he has changed. It's hard to say whether this person is the one before.
Secondly, it's more because the characters inside don't know much about Chen Guangrui, so when a similar person takes his place, as long as there is no big mistake (it doesn't matter if there is one, as long as it can go back), nothing will happen.
Another very big reason is that we actually pay little attention to others. We tend to pay more attention to ourselves, so we behave differently to others. It's hard for us to see it unless someone brings it up. After all, we don't care much, so we don't care even if others change.
Based on the above points, it is understandable why Liu Hong, who killed Chen Guangrui, has been a liar for eighteen years.