I don't think the problem is with intuition, though it's probably true that people don't realize that the absence of a freewheel is crucial to the function of a

I don't think the problem is with intuition, though it's probably true that people don't realize that the absence of a freewheel is crucial to the function of a unicycle. The problem is that a single example which differs on multiple dimensions from the "standard" bike (e.g. number of wheels, stability characteristics, steering, holonomic vs nonholonomic maneuverability) is highly ambiguous.