Hello Everyone,
My friend Samira talked about idealizing something in our mind so much that at one point when we have a chance to see it or live it we can witness and suffer from disappointment.
I think I read a scene like this in a book. it was Kinkakuji (The Temple of the Golden Pavilion) by Yukio Mishima. For years the main character in the book listens to the beauty of the Temple from his father. but when he finally visits the place he is shocked and disappointed but doesn't want to give up till he realizes the real beauty of the temple. And he becomes obsessed to it.
I think we all do this (idealizing something or someone) in our minds. and after some time we may start to afraid we may get disappointed or couldn't find the things that we are looking for in the future.
But at the same time idealizing somethings and someone may give us the courage to move on in life and try new things and get motivated.
So I think it's alright to idealize things. But never forget the reality of life. 
and at that Samira is right don't push your dreams forward. Do your best, and when you have a chance to use the opportunity to fulfill it, don't hesitate because you may be closer than you may think.