前事不忘，后事之师

lit. the cart in front overturns, a warning to the following cart (idiom); fig. draw lesson from the failure of one's predecessor; learn from past mistake

to learn a lesson from the mistakes of one's predecessor (idiom)

to review the old and know the new (idiom, from the Analects); to recall the past to understand the future

to learn from history (idiom)

to review the old and know the new (idiom, from the Analects); to recall the past to understand the future

lit. warning to the following cart (idiom); don't follow the track of an overturned cart; fig. draw lesson from the failure of one's predecessor