Historical clue formulations

• Dunderhead — 2023-04-20
• Lamebrain — 2010-02-15
• Chowderhead — 2008-12-30
• Lamebrain — 2008-06-16
• Birdbrain — 2008-05-21
• Dummy — 2004-06-03
• Birdbrain — 1999-12-19
• Dunce — 1995-05-03
• Pinhead — 1995-01-05
• Knucklehead — 1993-12-20