Historical clue formulations

• Fixate — 2026-05-21
• Stew (over) — 2025-12-25
• Have a bee in one's bonnet — 2025-03-25
• Dwell (on) — 2021-09-27
• Focus single-mindedly on something — 2021-07-26
• Hyperfocus — 2021-02-19
• Fixate — 2021-02-10
• Dwell (on) — 2021-01-02
• Fixate — 2019-04-28
• Become completely absorbed — 2018-03-03
• Think about only one thing — 2018-01-10
• Stew (over) — 2017-11-09
• Constantly worry — 2016-09-06
• Lose sleep (over) — 2016-07-27
• Worry compulsively — 2015-12-21
• Fixate (on) — 2015-06-07
• Preoccupy and then some — 2015-02-09
• Become fixated — 2014-10-12
• Become completely absorbed — 2013-09-28
• Have a fixation — 2012-10-25
• Keep thinking about, with "on" — 2011-09-12
• Dwell — 2009-09-03
• Preoccupy — 2008-05-22
• Dwell (on) — 2007-09-17
• Take hold of, in a way — 2007-03-10
• Have a one-track mind — 2006-07-12
• Preoccupy — 2005-11-17
• Dwell (on) — 2001-12-01
• Fixate (on) — 2001-07-10
• Haunt — 2001-05-03
• Haunt — 2000-06-13
• Haunt — 2000-05-28
• Preoccupy — 1999-10-07
• Can't stop thinking about something — 1999-05-03
• Haunt — 1998-01-11
• Haunt — 1996-05-05
• Preoccupy the mind of — 1995-06-06
• Preoccupy — 1995-06-02