And as anyone with children can tell you, the nipple is far from intuitive.
Explain.
That's a hilarious joke, made me LOL. If you want your product to be used though you have to think about what users already know how to do and try to build off of that. This is why baby bottles and skeumorphic design are popular and effective.
Since when does intuition exclude learned information? It's very much relevant to, say, what interfaces people have used before.