Don't count your chickens before they hatch
Meaning : Don't place

too much hope on something that you're not sure will actually happen.

Examples
Imran: I am quite confident that Eliud Kipchoge from Kenya is going to break the record for Men's Olympic marathon in Berlin this year.

Umair: There is no doubt he is hot favorite to win the race, but how can you be so sure? It's like counting chickens before they hatch. Let's wait and see, anything can happen.

Imran: I need 300 dollars to buy a laptop, if you lend me that money, I will return it to you next month, because a car manufacturing company has
called me for a job interview, I'm confident that I 'will get this job.

Umair: Don't you think you're counting your chickens before they hatch? I mean, you've not been ofered the job yet, and you're making plans based only on hopes.

I think if we assume that the next spy movie in the James Bond Series, "No Time To Die," would manage to carn $700 million worldwide, is like counting chickens before they hatch. It has already been delayed for the third time due to the coronavirus pandemic, the cinemas are closed, and
meanwhile, consumers' priorities may change.