1. The act of being stupid. Including actions, and thought.
2. Having something profoundly dumb happen to you.
Example 1: Girl: "I always thought that General Custer from from the board game Clue."
Guy: "That's the dumbest thing I've ever heard. You just had a Guthrie Moment."
Example 2: Oh shit! I just had a Guthrie Moment when I dropped my vodka on the fire and it went on my pants!