count your chickens before they hatch

count your chickens before they hatch

To celebrate, plan, or begin to take advantage of a potential positive future outcome before it has happened or been accomplished. Often issued as a warning and preceded by "don't." You're preparing your acceptance speech before even being nominated? Don't count your chickens before they hatch. Why are you begging to drive my car to school tomorrow when you still need to take your license test? Don't count your chickens before they hatch, babe!
See also: before, chicken, count, hatch