Possible Clues:

• "Who would have guessed?!"
• "Who would've thought?!"
• "Can you believe it?!"
• "Well, there's a surprise!"
• ''How amazing!''
• 'Who'da thunk it?'
• ''What a surprise!''
• 'Well, what do you know?!'
• 'Well, I'm really surprised!'
• "How surprising!"