The Brief: "Rent Free" is a response used often on Black Twitter indicating a person (or group of people) is spending too much time and energy thinking about a person, situation, or issue -- essentially allowing that topic to take up space in their mind(s) rent free.

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The slang phrase “rent free” is essentially short for saying someone “can’t stop thinking about a person, thing, or situation, because they live in someone’s mind rent free.
It is a response used often on Black Twitter to indicate a person is spending too much unnecessary time focusing on a certain subject. The phrase can be found in many Twitter threads, online debates, and sometimes memes.
The phrase seems to have evolved from a quote by advice columnist Ann Landers: “Hanging onto resentment is letting someone you despise live rent-free in your head.”
Ocasio is living rent-free in their heads https://t.co/sTNz4OJkd8
— Oliver Willis (@owillis) August 15, 2018
Nigerians be living rent free in everyone’s head 😭😭😭😭😭 https://t.co/oF1rtkD8PD
— homeboul (@stanthenigerian) May 19, 2020