What is the origin of the idiom "not count one's chickens" and when to use it?

The idiom "not count one's chickens" dates back several centuries and is rooted in the agricultural practice of raising chickens and the anticipation of future hatchlings. The phrase advises against premature optimism or overconfidence, emphasizing the need to wait for a specific event or outcome to occur before celebrating or making assumptions. It cautions that unforeseen circumstances could prevent anticipated results from materializing.