I remember when MAD Magazine did a "humorous" take on the 2-blade razor, suggesting a 3-blade razor would be funny (and it was). Now we have freaking 5-blade razors.
They also predicted seat belt nannies in cars (although the interface between the seat belts and starter was only there for a few years in the late 70's, early 80's).
3-ply TP -- why not? I could wander into TMI, but at this point I will let my sociological observations trump my scatological ones.