My wife is way smart (programmable thermostats)

A while back my wife and I were discussing how a programmable thermostat can save energy (money). I fell into the trap of thinking that it took just as much energy to heat back up as was saved while the house was cooling. She pointed out that savings is not while cooling down or heating up but while the house is sitting at the cooler temperature. In almost exactly the same words the Department of Energy says the same thing. She claims she's not a physicist--just that she studied physics--but I don't think I believe her, she thinks like a scientist, a super smart one.

I love you T.