What does it mean when the leader says you are 250?

To say a person is 250 means that he is stupid, not very sensible and stubborn and reckless.

The reason is: "Two hundred and five" means two hundred and fifty cents, which means "half-baked". (But in fact, one ounce of money is one thousand fen, and half a ounce of money is 500 fen.) From the above analysis, it is speculated that the term "two hundred and five" came into being in the late Qing Dynasty and the early Republic of China.

Usage of 250: as subject, object, attributive; it appears in spoken English everywhere. What needs special emphasis is: Two hundred and five is used for verbal ridicule, but it is definitely not a swear word or curse word.