take advantage of sb . 's ignorance
By surprise, the Chinese idiom, Pinyin is ch é ngq í B ù y ì, which means to take advantage of others' unprepared time. It comes from a new edition of Pinghua, a history of Jin Dynasty.
Notes on Idioms
Take advantage of, because; meaning: guess, expect.
The origin of Idioms
"The enemy says that I can't fight against the wind, so I should take advantage of it and attack it in a hurry. It's also the sophistication of this soldier."
Idiom usage
When the other party doesn't think of it, it means to do it. We should take advantage of it to attack the enemy.
take advantage of sb . 's ignorance
break the cauldrons and sink boats - chén zhōu pò fǔ
the dresses and ornaments of high officials in ancient times - yū qīng tuō zǐ
act in undue confidence of one 's own ability and look down upon others - shì cái ào wù