I have witnessed many ignorant foreigners at the check outs in the supermarkets, one refused to move his trolley, I asked him to as did the check out girl, he just shook his head and walked away with his shopping leaving the trolley blocking the exit, another left his empty basket on the conveyor saying it was not his job to move it when asked to do so. These are just a couple of incidents, no wonder some Thais are sourpusses towards foreigners who tend to look down on Thais as if they are lower class.