Rent-free
Etymology
From the full idiom “living rent-free in your head,” which circulated for decades in self-help and recovery contexts (the advice not to let a resentment occupy you cost-free) before being clipped and popularized as a standalone tag across social media in the 2010s and 2020s. Its exact coinage is unclear.
adjective · /RENT-free/
Occupying your thoughts obsessively and without your consent — as in something “living rent-free in my head.”
What it names
It captures the odd asymmetry of an obsession: a person, insult, or embarrassing memory takes up mental space it never earned and pays nothing for it. The phrase is usually a half-joke about your own inability to let something go, or a jab that someone else is more fixated on you than they’ll admit.
Example
That one typo I made in the company-wide email is living rent-free in my head.
Related idea
Softer than an intrusive thought, which is clinically unwanted; rent-free is often affectionate or grudgingly amused.
See also