Is it really agonizing to suddenly realize that you want that which you can never have … forever banishing said longing to a world of illusion, fantasy and imagination?
Yes. Yes it is.
"The years that are gone seem like dreams--if one might go on sleeping and dreaming--but to wake up and find--oh! well! perhaps it is better to wake up after all, even to suffer, rather than to remain a dupe to illusions all one's life." ~Kate Chopin, The Awakening
"What wild imaginations one forms where dear self is concerned! How sure to be mistaken!" ~Jane Austen, Persuasion