When someone generally misunderstands social behavior as a whole as has an unnatural degree of innocence still left in them. These instances are categorized by naivety and general ignorance about the topic at hand. Also relates to: being overly optimistic about a situation or society as a whole.
Person 1: "Dude, I'm getting so hammered tonight."
Person 2: "That sounds like it would hurt..."
Person 1: "I can't believe you're pulling a Benji on me right now. You're not coming with us."
The act of acquiring a rope, tying said rope into a noose, and hanging oneself. The phrase "Bennington" is a reference to Chester Bennington, whom had used this method of suicide.
I'm tired of math class. I'm Pulling a Bennington. I'll catch y'all folks on the other side.