I parked up in Tesco park and in the car next to me was a women eating a sandwich but her car headlights were on. When I come back out after doing my shopping she was still there with the lights still on. I assumed she'd forgotten to turn them off and motioned for her to roll down the window and I told her that her lights were on and they might drain her battery.
She responded by telling me to 'f off and mind your own business'. Was I wrong? I just thought I'd want someone to tell me. It's really not that serious