Historical clue formulations

• "Oh, yeah?" — 2025-03-28
• "Are you pulling my leg?" — 2023-07-16
• In actuality — 2022-05-17
• "You sure about that?" — 2021-09-09
• "I'm not kidding!" — 2017-01-24
• "Are you kidding me?" — 2012-05-20
• Remark of exasperation — 2005-01-29
• "For sure?" — 2004-01-18
• "Come on now!" — 2003-05-07
• "No kidding!" — 1996-06-10
• "Is that so!" — 1995-12-07
• "Is that so?" — 1994-08-15