Related Clues:

• 'Ha!'
• 'Fat chance'
• Forehead-slapper's cry
• "Of course!"
• "A likely story!"
• 'Boy, am I dumb!'
• "How could I be so stupid?"
• Skeptical exclamation
• Sarcastic reply to an assurance
• 'That'll be the day!'
• "Baloney!"
• 'Like that's gonna happen!'
• "How obvious!"
• Doubter's scoff
• "Yeah, right"