How did the story of calling a deer a horse come about?

Deer and horses are two fundamentally different animals, even children can't tell them apart. However, in the history of China, some people openly called deer horses in the court of the emperor and the Manchu emperor. Strangely, everyone followed suit. The emperor felt strange and suspected that he was sick, dizzy or insane, so he invited Taibu, the official in charge of divination in the palace, to come to divination. Unexpectedly, Tai Bu calculated for a long time that the deer was a horse. This strange thing, which intentionally turns black and white and confuses right and wrong, happened in Qin Ershi's Hu Hai period. It was the Prime Minister Zhao Gao who directed this ugly play, and since then, he has left an absurd story of "referring to a deer as a horse" in history.