Historical clue formulations

• Declining late in life — 2025-06-07
• No longer all there — 2018-04-19
• Declining due to age — 2018-02-11
• Mentally infirm — 2017-09-21
• In one's dotage — 2016-11-20
• Beyond reason? — 2011-11-10
• Doting — 2011-07-14
• Definitely past one's mental peak — 2011-01-03
• 90% off? — 2011-01-02
• Having some memory problems — 2009-10-09
• Softheaded — 2006-05-03
• In one's dotage — 2003-12-21
• Declining, in a way — 2003-04-18
• Dotty — 2000-11-10
• Not thinking well — 2000-09-03
• Having lost it — 2000-03-25
• More than forgetful — 1998-10-11
• Dotty, perhaps — 1997-03-27
• Addled by age — 1996-06-26
• More than forgetful — 1994-05-04
• Failing — 1994-03-04