Related Clues:

• Forehead slapper's exclamation
• Without doubt
• "I'm not stupid, y'know"
• "C'mon, too easy!"
• Sarcastic retort
• 'Obviously!'
• ''How silly of me!''
• 'Well, obviously!'
• ''I should've thought of that!''
• "How dumb can I be!"
• 'I'm such a dope!'
• ''No kidding, stupid!''
• 'Isn't that obvious?!'
• "How silly of me!"
• "Like, how did I make THAT mistake?"