The Brief: "Not me" is a phrase used by an individual to poke fun at their own embarrassing, toxic, or self-absorbed behavior.

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The phrase “Not me” is used by social media users to call themselves out in a self-deprecating manner. It is typically done used to poke fun at their own embarrassing, toxic, or self-absorbed behavior.
NOT ME SOBBING AT THIS FOR THE PAST HOUR pic.twitter.com/wTh8QLYdd8
— heather (@gomezxhalsey) January 27, 2021
“Not me” is relative to the phrase “Not you” or “Not y’all” which is used to critique and call out others as well as issues in mainstream culture.
Not y’all advertising parties in the middle of a pandemic 💀 how embarrassing
— 𝐤𝐢𝐦🪐 (@kimberlynemira) January 20, 2021
not y’all in the quotes auditioning to become ivy park ambassadors https://t.co/6I4PODdKiM
— 𝐂𝐡𝐚𝐧𝐞𝐥 ♡ (@LondynnTheDoll) January 27, 2021