Water usage is probably my biggest. Living in a high desert, my wife and MIL see no problem with filling one side of the sink with hot soapy water to wash a few dishes because “that’s just how I’ve always done it”, to watering the grass and plants for hours. All of this makes me mental.
Keep right except to pass. The passing lane is for passing.
When I was driving in Mexico, I learned this is possible! They’re very consistent with this.
California (not sure about other US states) on the other hand … people will purposely drive in the left lane, block traffic, and then get mad at you when you pass them on the right.