Ours doesn't have numbers, just "low", "high" and "comfort zone". We have baseboard heat (terribly slow/ineffecient) and a separate dial for each room.
Our thermostat routine is,
I turn on the heater, 'cause it's cold, to "low-comfort-zone".
Sometime while I'm at work, DH decides it's too hot, and opens the bathroom window, and turns on the swamp and the room AC. (I am serious.)
He turns off the swamp and the AC right before I get home.
I get home to a freezing house, despite all the heaters being on. I go to the bathroom, sit on the freezing seat and see that the window's open.
A fight ensues.
He swears up and down that he will turn off the heaters instead of opening the window. Also swears not to run swamp and AC simultaneously. Also swears to run neither of these with the heaters on. Also swears not to run AC or heater with window open.
Power bill (which DH pays) arrives, DH wonders how we used $180 of power in 840 sq. ft.
And repeat from the beginning....
Not exaggerating about any of this. Thermostat is just about the only bone of contention in our marriage.