When somebody overrates himself, he is often warned: "Don't be a mantis trying to stop a chariot." The saying comes from a legend dated back to the Spring and Autumn Period.

One day, the King of Qi went out for a hunting with his men. The carriages were going along, when suddenly a mantis stood in the middle of the road with its sickle-like forelegs opened. It was obvious that he was trying to fight against the carriage to hold it back. Surprised at the case, the King of Qi ordered to stop and asked what creature it was. When he was told it was called mantis, and it would go well up to bridle decisively when it was challenged. The King sighed with exclamation at its braveness. He mused a moment and added: "It's a great pity that it is not more than an insect. If it were a man, he must be the bravest warrior in the world!" Then the King ordered his carriages turn around it to leave the mantis there standing martially.

When the persons around heard the King's words, they were well touched and determined to devote themselves to the country.

As time passed, the meaning of the phrase changed to its opposite. Now it means that someone overrates oneself and try to hold back an overwhelmingly superior force.