"What comes to mind when you see the phrase, 'change the unchangeable'?" If you write "you" as "u", it makes you sound like a bored teenager trying to act "cool". This sounds like a topic for the Discussions section, so I'll just leave my corrections.

I immediately think of the song, "The Impossible Dream," from the musical "Man of La Mancha:" https://www.youtube.com/watch?v=RfHnzYEHAow "To dream the impossible dream To fight the unbeatable foe To bear with unbearable sorrow To run where the brave dare not go To right the unrightable wrong To love pure and chaste from afar To try when your arms are too weary To reach the unreachable star..."

If you’re going to post vague and out-of-context questions, then you shouldn't really expect an answer for your question, I not being mean, but you can’t really post random question from your English text-book, to me it seems like you’re trying to finish your English homework but lost track.