Well I think it is a safe notion to dream. Not in the literal sense but dream of a better future or dreaming of aspirations.
But when does your judgement become clouded to where you do not realize that it is nothing more than a pipe dream?
Pipe dream: unrealistic hope daydream, false hope, fantasy, fool's paradise, golden dream, pie in the sky, wishful thinking.

When you have your sites set on something for so long it may be hard to come to terms with the reality that it will never happen.