When KISS isn't

So, KISS is an acronym for Keep It Simple Stupid.  When you hear your aging parent screaming that the expensive programmable thermostat is an elephantine pile of dung (in not so nice terms) you realize that even though your impulse was KISS -- all she has to do is switch from heat to cool as the seasons dictate -- that is not enough.  First of all, you forgot she can not see the symbol that means the AA battery needs to be changed even though it is very obvious and plain to see because she doesn't expect to see such a thing on a thermostat.  Secondly, she expects that she has to turn it up and down because that is the way thermostats have worked all her life and has completely forgotten that all she has to do is switch from heat to cool or the reverse because you made it easier for her.  Sigh.