Originally Posted by Titanium Silver
Never tried it, but I'm pretty sure if you have comfort access, then you turn off the engine by pressing the button once, but you don't get out and lock the door, all the electrical stuff stays on including the lights and the radio etc.
Maybe OP turned off engine, and got out without pressing the lock button to completely shut down the car. Not sure if the car would override and turn off on its own.
... Could be it. I have comfort access and several times left light switch ON in manual mode. Car shuts off lights when I lock car and I only realize I left it switched to "ON" when I start up the engine the next day.