Pulling a Benji

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."