But... who chooses which is the correct option and which is not? Is not it the same little voice?

We can't see alternative scenarios, so we can't know if what happened was the best or the worst. But it does not matter as long as we accept it.

As long as we do what we believe is right the moment we do it, regardless of the future or the past, or appearances, or what others assume, but what we think at that precise moment that is right, then it was the best option.