Why full-filling desires is close to impossible

Imagine you are into a girl, she calls you, and you ask her if we could go out and she says, "we could, I will confirm in some time, it's 90 percent yes but give me some time to confirm. "(This is where you should know she is not coming, but lol I am a man).

By the time she is thinking, you say to yourself the probability in my favor is 0.9, what could go wrong. But then you think what's the probability of that the 0.9 probability which is in my favor actually works out which is 1/2. But then you think what's the probability of this probability to work in my favor which is again 1/2. And it goes on.

So the chance of the girl saying "Yes" for you is = 0.9*0.5*0.5*0.5*0.5*.......= ~0

So mathematically she is not coming, so by having desire you are actually losing it out.

And obviously, every desire brings pain, so I am finding ways how can I overcome desires because they are not just bringing pain but also I am losing out on those things.