Not all Chicken eggs do hatch, so it is premature to say that you will have 10 chicks because of 10 eggs you saw. Some eggs are bad and won't hatch. Example; If you made a business, don't expect to earn a million because you might earn less. This saying would just want to say, we need to lower our expectations.

Don't count your chicken before they are hatched. = It's too early to count on things. To take something into account. To reckon with something. To plan ahead. For example: After learning this new language I will teach you. - No. Just start to learn it yourself. We talk about teaching it later. When you know more about it.

不要过早乐观 凡是不要期望過早或過高