The only viable response to something so utterly shocking that it leaves you in the ultimate state of confusion and disbelief.
*Phone rings at 0330*
Me: "Nnnnnuughhh... hello..?"
Team Chief: "Hey, just checking to make sure you're good to come into work at 0900."
Me: "Fucking what?"
Careful For What You Wish For is used to warn a person about their wish they want to come true and tell them that it might not the thing they will envison later on.
Person 1: Man, I wish to become a successful hiphop rapper!
Person 2: Careful what you wish for though! it might come at you ten fold in the most unexpected way.