Possible Clues:

• Monarch eliminated from European kingdom? Certainly not!
• Never!
• "Impossible!" and the theme of this puzzle
• "I don't think so!"
• 'That's too hard to believe...'
• "That's too hard to believe..."
• "Ain't happenin'"
• Refusal to Jose?
• "Forget it!" (and a clue to this puzzle's theme)
• Emphatic refusal of oxygen: 'Enjoy!' was misconceived