The process of ruminating on what one should have done or said in an interaction that just transpired or transpired earlier. During PIIR the individual typically undergoes feelings of self-abuse, anger, and/or embarrassment.
"Dude, I could have earned way more brownie points with Paige had I just tried to be more flirty. Now she probably thinks I'm a wank or thinks I’m not interested in her. Wait. Shit, SHIT! I gotta snap out of this PIIR."
"You're not a wank. And what's PIIR?"
"Post-Interaction Idealistic Rumination."
"That's quite a mouthful."
"Indeed."

or:

"I just agreed to go to church every Sunday morning with my neighbor. What the shit was I thinking?! I should have told him I'm busy literally every Sunday morning! #Fuckmylife."
by Richard Flavor October 5, 2014
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