The theory reads as follows:

Husbands and wives have opposing opinions as to the utility and appearance of any object.

In other words,

Men care less about what it looks like as long as it works good, and women care less about how it works as long as it looks good!

I developed this theory in 1982 after owning my first computer — a Sinclair ZX-81 — for several months. Before I finished tinkering with it, there were peripherals and plug-in devices spread out all over the desk. It worked great but was an ugly mess! And got my computer desk moved from the living room to a back room for that reason! Which led a friend at the time to propose the following qualifier to the theory:

The closer to the living room it is, the better it has to look!

So far I have yet to find any married couple for whom this theory doesn't apply. And while first aplied to computer hardware, this theory has since proved to apply generally to almost any object: cars, furniture, household appliances, etc., etc.!