Have you ever finished shopping and have your hands full; and you were about to open the door with your foot, when somebody coming into the store opens the door and hold it so that you can exit the store. After you walk through the door, the person say in a sarcastic tone of voice; “you’re welcome.” Because you neglected to say “thanks.“

Well what would be your reaction? You did not ask for their help, did the person open the door expect some type of gratitude? Plus the situation was that allowing you to exit before the person can enter. Both couldn’t walk through the door at the same time.

Well, I personal don’t like sarcasm and my gut reaction would be telling the person to go fuck themself. But since the person did hold the door open for me, I give them the respect and rather than cussing them out, I usually say nothing and keep it moving.