Keiva wonders about the origin of "You're all wet!" in another post, and it brought to my mind another expression that means someone is naive or inexperienced: Greenhorn.

But why greenhorn? Anyone know? Bovine origins? I never seen no cow wit green horns, no never.

Edit: this baby pretty quickly got shanghaied by the uniform debaters so I thought I would edit the title so people could remember where to find that scintillating discussion....!