One thermostat, two very different floors
A single thermostat can only read the spot where it is mounted. In a two story Conroe house, heat rises, so a thermostat in the downstairs hall shuts the system off before the upstairs has caught up. A bonus room over the garage, a converted garage or an addition tied into the original ductwork often sits at the end of a run it was never designed for. Rooms facing west take the afternoon sun and climb in temperature while the hall stays comfortable.
The result is a house managed by averages. Someone is always a little too warm or a little too cold, the thermostat keeps getting nudged, and the equipment runs hard trying to satisfy one reading for the whole building.
