I think this is a good example of the Dunning Kruger Effect -- however poorly it matches with what the original article proved -- of "when you're a beginner, you don't realize how much of a beginner you are."

A non-expert climber figures a tough hike is basically like any other hike they've been on, only a little harder. They don't recognize how large the gulf is between a tough hike up a mountain and a treacherous life-or-death situation.