Don't count your chickens before they are hatched. Don't change your horses in midstream. These two sentences are:

Question

Quizplus · Accepted Answer

Don't count your chickens before they are hatched means that you should not anticipate a good outcome to some event until the event has actually taken place. But don't change your horses in midstream means that you should not make major changes in some activity that has already begun. These meanings are not related to each other so they are neither similar nor contradictory.

Don't Count Your Chickens Before They Are Hatched