Rude people tend to be the ones that hate life witb every fiber of their being so they let their misery expand through everything they come in contact with. Or the entitled ones, too busy sitting on their high horse , staring at their phone to even realize theyre being rude. I think reminding them is needed sometimes (: a simple sarcastic "your welcome" tends to work for me. It gets really fun when you have a full on conversation with yourself in front of them "oh thankyou! How kind!...oh youre very welcome sir have a beautiful day!" You may look crazy but they'll pay attention long enough to get the message (;