Hay-Whitton's theory of male psychology: every man is trying to turn into his father, or trying not to. This explains at least 90% of human male behaviour.
Sigmund Freud said something similar about male progeny, I believe. @-)
Damn. I also thought of cyborgs, hand-pedalled quadricycles for cripples, and soap-filled scouring pads, only to find I was too late for the party. :(