What does Xu Wenchang mean by that? I think it has three meanings. First of all, the fine arts shop used to be a dual manager system of Hefang. Later, both of them were removed from their posts, and then Zhai Xiaoyun arranged a colleague with dual management, namely Yu Hualong, to be the acting manager, which was "something" in itself. More "magic" is that Yu Hualong is playing the manager, and he really thinks of himself as the manager. Xu Wenchang's words are worrying about Yu Hualong's emotional intelligence.
Focus: Who promoted Yu Hualong to be the acting manager? It's the general manager Zhai Xiaoyun, who doesn't deal with Xu Wenchang. He just ordered the ichthyosaur and didn't lose his mind at all. However, Zhai Xiaoyun knows that everyone in the fine arts shop belongs to Xu Wenchang and will not stay. It is only a stopgap measure to let Yu Hualong be the acting manager, and it will be replaced sooner or later. This corresponds to Xu Wenchang's sentence, "Did you really regard yourself as the manager in the Ninth Five-Year Plan?"
There is another meaning, that is, 1985, when Xu Wenchang acted as the manager, he was a little "sour". After all, he was the manager's eldest brother in 1985. ...