I greatly expanded my appreciation of human nature and illustration, beginning in the spring of 1970, sitting on the padded, dayglo green toilet seat at People's Cycle, perhaps the first east coast used motorcycle parts and repair shop.
The bathroom had a full selection of Zap comix, which featured Mr. Natural, and a variety of other characters including bikers, Fritz the cat, many naked women, an even Crumb himself.
A formative experience for me, as I continue to use bathrooms to this day..