Don't count chickens before they hatch
不要过早乐观，在事情未确定前不要做计划或假设，以免失望。
劝告他人不要过早下结论或做计划时使用。
英文释义
Don't make an assumption about something that does not have a definitively predetermined outcome.
例句
I know you're excited, but don't count your chickens before they hatch.
典故来源
源自伊索寓言，讲述一个农妇在鸡蛋未孵化前就幻想卖鸡赚钱，结果蛋被打碎。